Chief Justice Ma: 1. I agree with the Judgment of Mr Justice Cheung PJ. Mr Justice Ribeiro PJ: 2. I agree with the Judgment of Mr Justice Cheung PJ. Mr Justice Fok PJ: 3. I agree with the Judgment of Mr Justice Cheung PJ. Mr Justice Cheung PJ: 4. At the conclusion of the hearing, we dismissed this appeal. These are my reasons for doing so. The facts 5. This appeal concerns the requirement under the common law offence of attempting to pervert the course of justice that the accused’s act has to have a tendency to pervert the course of justice, in the context of an investigation by the Independent Commission Against Corruption (ICAC) against the appellant. 6. The appellant used to be a staunch supporter of Mr C Y Leung in his (successful) bid to become the Chief Executive of the Hong Kong Special Administrative Region (HKSAR) in the 2012 election. However, the relationship between the two turned sour after Mr Leung assumed office. Days following some public criticism of Mr Leung’s policies by the appellant in the local media, the appellant was arrested by the ICAC on 8 January 2013 for having conspired with others to commit an offence contrary to section 9(3) of the Prevention of Bribery Ordinance[1] and section 159A of the Criminal Procedure Ordinance.[2] The alleged offence arose out of the acquisition of an oil field in the United States by a listed company, Pearl Oriental Oil Ltd, of which the appellant was the Vice-President and Executive Director. After attending a video recorded interview, the appellant was released on bail later that night. 7. On the following day, the appellant through his personal secretary sent an email to the Chief Executive complaining about the ICAC arrest and investigation. In the email, he protested his innocence and claimed that it was a framed up charge against him. He expressed the strong suspicion that it was orchestrated by the Chief Executive in revenge for his criticisms against his policies. In the penultimate paragraph of the email, he urged the Chief Executive to: “make careful consideration from a political and from the overall perspective and urgently halt the groundless persecution against me, so as to avoid causing a huge shock to society!”[3] 8. In the final paragraph, he concluded his email by asking the Chief Executive to remind the Commissioner of the ICAC “to ask his subordinates to be extra cautious, or else a political bomb will be detonated!”[4] 9. On the same day, the appellant through his personal secretary sent another email of essentially identical content to the Commissioner. 10. On 10 January 2013, the appellant again through his personal secretary prepared a letter addressed to the Chief Executive and copied to the Commissioner, which letters were delivered to the Chief Executive’s Office and the ICAC Headquarters respectively. In the letter, the appellant accused the Chief Executive as the instigator of the “persecution” against him by the ICAC, and he once again proclaimed his innocence. He threatened that if the ICAC did not stop the groundless accusation against him and the other directors of the listed company and other people involved in the case, he would: “immediately announce the Call for Leung Chun Ying’s Resignation to domestic and overseas media and to the Central People’s Government which contains shocking insider information to perish together with the ungrateful man who returns kindness with evil … .” [5] 11. In the following paragraph, he urged the Chief Executive to “take decisive measures immediately to halt the persecution”[6] against him and the other directors and management personnel of the listed company. He added: “Please promptly instruct the Independent Commission Against Corruption to stop the unreasonable investigation.”[7] 12. On 20 August 2013, the appellant was charged with one count of “doing acts tending and intended to pervert the course of public justice” by the ICAC. The particulars of the charge stated that by his two emails and the letter, he sought by asserting his past dealings and association with the Chief Executive, by threat or by intimidation to influence the Chief Executive and/or the Commissioner to terminate an investigation being carried out by the ICAC against him and/or others. 13. In 2015, the Pearl Oriental case involving the appellant and some others went to trial in the High Court on two counts of conspiracy to defraud together with one count of dealing with the proceeds from an indictable offence.[8] On 20 May 2015, the jury unanimously found the appellant not guilty on all charges and he was acquitted accordingly, whereas two co-defendants were found guilty and convicted of some of the charges. (A third co-defendant had absconded before the trial.) The proceedings below 14. However, in relation to the charge against him of attempting to pervert the course of justice, the appellant was tried in the District Court before HH Judge Frankie Yiu and was convicted on 29 February 2016.[9] He was sentenced to 18 months’ imprisonment. 15. On 2 March 2018, the Court of Appeal dismissed the appellant’s appeal.[10] On 25 May 2018, the court granted the appellant’s application for a certificate that points of law of great and general importance were involved in its judgment which ought to be considered by this court – these became Questions 2, 3 and 4 in this appeal: “[Question 2] Given the mandatory duty to investigate alleged or suspected offences under section 12(b) of the Independent Commission Against Corruption Ordinance (Cap 204) (‘the Ordinance’)[11] and the concurrent lack of any statutory discretion as in section 12(a) of the Ordinance: (i) Does the Commissioner of the Independent Commission Against Corruption (‘the Commissioner’) have an operational discretion based on the Common Law which is identical in nature to that possessed by the UK Commissioner of Police; and (ii) If the answer to (i) is in the affirmative, is the nature of this discretion which is based on the Common Law capable of overriding his mandatory duty to investigate under section 12(b) to the extent of empowering him to stop any ongoing criminal investigation on bona fide grounds? [Question 3] Reading Article 57 of the Basic Law in conjunction with sections 5, 12, 14-17 of the Ordinance, does the Commissioner’s accountability to the Chief Executive of the Hong Kong Special Administrative Region (‘the Chief Executive’) include matters of operational issues concerning criminal investigations of individual cases, and is not merely confined only to matters of the direction and administration of the Independent Commission Against Corruption? [Question 4] If the answers to Questions [2] and [3] above are all in the affirmative, does the Chief Executive have the same operational discretion which is based on the Common Law as that of the Commissioner which is capable of overriding the Commissioner’s mandatory duty to investigate under section 12(b) of the Ordinance to the extent of empowering the Chief Executive to direct the Commissioner to stop any ongoing criminal investigation on bona fide grounds, or does the Chief Executive have any additional or other legal power to direct the Commissioner to stop any ongoing criminal investigation on bona fide grounds?”[12] 16. These three questions arose from the arguments between the prosecution and the appellant, both in the District Court and before the Court of Appeal, as to whether what the appellant had done had any tendency to pervert the course of justice, the appellant’s argument in gist being that it did not since neither the Chief Executive nor the Commissioner had the legal power to stop an ongoing ICAC investigation. In other words, despite the appellant’s threats and intimidation expressed in the emails and letter, the Chief Executive and the Commissioner simply had no legal power to do what the appellant wanted them to do. 17. Although the Court of Appeal rejected this contention of a lack of legal power,[13] it nonetheless regarded the legal issues raised as having great and general importance meriting consideration by this court. As will be seen, notwithstanding that the Court of Appeal has addressed the issues involved in Questions 2, 3 and 4 in some detail, I do not find it necessary to do so. The Appeal Committee’s certified question 18. On 2 November 2018, the Appeal Committee granted leave to appeal to the appellant on the basis of an additional certified question raising a point of law of great and general importance, which it regarded as a prior question to the three questions certified by the Court of Appeal.[14] This prior question thus became Question 1 in this appeal: “(Question 1) Where an accused seeks to cause a person to stop or otherwise interfere with a criminal investigation, is it incumbent on the prosecution, on a charge of attempting to pervert the course of justice, to establish that the person approached by the accused could, by the lawful exercise of a legal power he possesses, stop or interfere with the criminal investigation in order to prove that the accused’s act had a tendency to pervert the course of justice?” 19. The Appeal Committee pointed out that Questions 2, 3 and 4 would arise if, but only if, Question 1 was answered affirmatively. In other words, on the facts of this case, if it was unnecessary for the prosecution to establish that the Chief Executive or the Commissioner could, by the lawful exercise of a legal power that he possesses, stop or interfere with the criminal investigation in order to prove that the appellant’s acts had a tendency to pervert the course of justice, Questions 2 to 4 would not arise at all. For this reason, Question 1 assumes great importance in this appeal. The general legal principles 20. The law on the common law offence of attempting to pervert the course of justice is well established. The offence is “the doing of some act which has a tendency and is intended to pervert the administration of public justice”.[15] The actus reus is the doing of the act with the prohibited tendency and the mens rea is the intention to pervert the course of justice.[16] So far as the actus reus is concerned, as this court has pointed out: “(a) Although it is called an ‘attempt’, it is a substantive offence. But like an inchoate offence, it is committed even where the act with the prohibited tendency does not actually result in interference with the course of justice. (b) A person’s conduct has a tendency to pervert the course of justice if it has a tendency towards ‘impairing (or preventing the exercise of) the capacity of a court or competent judicial authority to do justice’. (c) The tendency must involve impairing the administration of justice in curial proceedings. Conduct with a tendency to result in unlawfulness which does not interfere with curial proceedings does not constitute the offence.”[17] 21. For an act to have a tendency to pervert the course of justice, it must have a tendency to bring about a miscarriage of justice in curial proceedings. It is not necessary for such proceedings to have been instituted at the time of the acts in question but the relevant acts must have a tendency and be intended to frustrate or deflect the course of curial or tribunal proceedings which are imminent, probable or even possible.[18] 22. Investigations by law enforcement agencies do not by themselves form part of “the course of justice” so that acts which hinder or interfere with their investigations are not sufficient in themselves to constitute a perversion of the course of justice. However, if such acts of interference carry a tendency and are intended to pervert the course of justice in relation to curial proceedings which may result from the investigation, they are capable of founding the offence.[19] The present appeal 23. On the facts of the present case, there is no dispute that even though no curial proceedings were in place at the material time, subject to the issues raised in this dispute, the appellant’s acts of asking the Chief Executive and the Commissioner to stop the investigation which might result in criminal prosecution against himself and others did fall within the ambit of the offence of attempting to pervert the course of justice. 24. The central focus of this appeal is whether the appellant’s acts had a “tendency” to pervert the course of justice, that is, to terminate or otherwise interfere with the ICAC investigation. Essentially, the appellant’s position is that there was no such tendency, or more precisely, the prosecution has not proven beyond reasonable doubt that there was such a tendency. Indeed, that was the genesis of the legal issues which eventually became the three questions of law certified by the Court of Appeal. Mr Joseph Tse SC (Ms Doris Ho and Mr Byron Tsang with him), for the appellant, pointed out that at trial, the prosecution had adduced no evidence on how the Chief Executive or the Commissioner could cause or bring about the termination of the ICAC investigation, apart from relying on various legal provisions and some common law principles to say that they have the legal powers to do so.[20] That was how these legal provisions and principles became the subject of contention before the lower courts. HKSAR v Tsui King Sing 25. In the printed case, as in the courts below, Mr Tse placed considerable emphasis on the case of HKSAR v Tsui King Sing[21]in support of his argument that it was not proven that the appellant’s acts had any tendency to pervert the course of justice. In Tsui King Sing, the defendant was a co-owner of a coffee shop which was burgled by a former employee. He approached the father of the employee and offered to either “drop” the case against her, or not attend court as a witness, for a sum of $80,000. By that time, the employee had been arrested, interviewed under caution, apparently charged and, given the time period involved, no doubt had been brought before a magistrate. The defendant was convicted after trial of doing an act tending and intended to pervert the course of public justice. His appeal to the Court of First Instance was allowed on the ground of impossibility, that is, the case was, by the time of the conversation between the defendant and the father, likely beyond any stage (if such a stage ever existed) of the defendant being able to prevent the prosecution proceeding, and that the defendant’s offer to not give evidence was entirely meaningless as he was not (and was never intended to be) a witness in the proceedings.[22] 26. Agreeing with counsel’s submission, McMahon J observed that whether an act has a tendency to pervert the course of justice is a question of fact. To pervert the course of justice means to “deflect, frustrate, impair or hinder” the ability of a court to administer justice.[23] The learned judge went on to point out: “26. Of course it was for the prosecution to prove the appellant’s offer to ‘drop’ the prosecution had a tendency to pervert the course of justice, and it seems to me there was insufficient evidence before the Magistrate so as to allow him to conclude beyond reasonable doubt that it was possible for the appellant to pervert the course of justice in the way the appellant had offered. 27. There was no evidence before the Court, as I understand it, as to whether the police would or could take such a request from the victim of an offence, such as the burglary of a coffee shop, into account in deciding whether to proceed with the case. It may be in many cases an act by a defendant will manifestly have a tendency to pervert the course of justice and little or no evidence will be required to establish that fact, but in the circumstances of this case, such evidence should have been called by the prosecution. Without such evidence it is difficult to see how the appellant's offer, regardless of his quite obvious intent, could have been found to have the required ‘clear or manifest tendency’ of perverting the course of justice: HKSAR v Wong Shing Yim & Others and R v Rogerson & Others (1991-1992) 174 CLR 268. 28. It seems to me that the Magistrate's finding, set out above, was really based on his own understanding of how police may react to a request to ‘drop’ a case and not on the evidence before him. Equally there was no evidence as to the possibility of the appellant becoming a witness in the trial of PW1's daughter. Factually, it seems to me that, on the evidence, there was some doubt as to whether in the circumstances of this case it had been proven the appellant's offer had the necessary tendency to pervert the course of justice.” My views 27. I agree that it is a question of fact in each case whether the defendant’s act had the tendency to pervert the course of justice. If the act is not proven to have such a tendency, no offence has been committed. Bribing a witness to give false evidence when the witness has already completed his evidence in court may well be one such example. Threatening a juror with unpleasant consequences if he should find the accused guilty when the jury has already returned a verdict and been discharged is another such, perhaps extreme, example. In both these examples, and also in Tsui King Sing as regards the offer to drop the case, the relevant act of the defendant may, as a matter of fact, simply have come too late to have any tendency to pervert the course of justice. 28. Lack of a tendency to pervert the course of justice could also arise in other situations. The offer not to give evidence as a witness in Tsui King Sing when the defendant was not and was never intended to be a witness in the criminal proceedings provides another example of the lack of a tendency to pervert the course of justice. McMahon J essentially found that the defendant was simply not relevantly connected with the criminal proceedings such that his offer had no bearing on the proceedings. A variation of the same theme may be where the person in question, though not totally unrelated in some sense to the proceedings, is simply, say, too junior or too remotely connected to have any possible effect on the proceedings. Thus, to bribe a security guard of the court building where the Court of Appeal sits to influence the outcome of a pending appeal before the court would be one example. 29. However, contrast that last example with the situation where the offer of a bribe is made to one of the appeal judges hearing the appeal. The tendency to pervert the course of justice in this latter example would be manifest and plain. 30. Vary this example slightly. What about a bribe or a threat made to the spouse of the judge hearing the case? In my view, while again depending on all the facts, it is obviously highly likely that the bribery of or threat to the spouse would be found to have a tendency to pervert the course of justice. 31. This brings me to the type of situation faced in this appeal, that is, approaching the Chief Executive and the Commissioner with a view to stopping or otherwise interfering with an ongoing ICAC investigation. The Chief Executive and the Commissioner are, respectively, the head of the HKSAR[24] and the head of the ICAC.[25] Moreover, the Chief Executive is the very person to whom the Commissioner is accountable in respect of his work.[26] In my view, writing to them asking them to stop an ongoing ICAC investigation, with the threat that otherwise a huge political bomb would be detonated, plainly involves a tendency to pervert the course of justice. This case is far removed from the examples I gave earlier of situations where a court may find that there was no tendency to pervert the course of justice. 32. First, the emails and letter were written at a time when the investigation was ongoing. There is no question of the matter having gone past the stage where it could be interfered with. 33. Secondly, by virtue of his position, the Commissioner was directly and most relevantly connected with the ICAC investigation. So far as the Chief Executive is concerned, he is the person to whom the Commissioner is accountable. Moreover, he is the head of the HKSAR. He is plainly a relevant person connected with the ICAC investigation. 34. To suggest, as the appellant did, that in order for the approaches to them to have a tendency to pervert the course of justice, the Chief Executive and the Commissioner must have the legal power to stop the investigation, is to overlook the reality of the situation (regardless of whether, as a matter of law, they do or do not have the legal power to terminate the investigation). Given the unique constitutional and legal position of the Chief Executive, he is undoubtedly in a position to influence or otherwise affect the Commissioner’s and, through the Commissioner, his officers’ handling of the investigation, if not effectively to stop it altogether. For instance, he may seek to persuade the Commissioner, or to put pressure on him, to take steps or adopt courses that are favourable to the appellant. That the Chief Executive may or may not be successful in what he seeks to do is not the point. In my view, what he can do (if he wants to or is forced to) would be quite sufficient to constitute a tendency to pervert the course of justice, particularly when one remembers that the attempt to pervert the course of justice need not be successful.[27] Bribing a witness who is prepared to accept a bribe, and attempting to bribe an honest and upright witness who cannot be bribed makes no difference in terms of the commission of the offence. The person offering the bribe commits the offence of attempting to pervert the course of justice in both cases. Likewise, whether the bribed witness’ evidence is accepted by the court is irrelevant. Offering the bribe to him amounts to an offence. 35. Similarly, given the position of the Commissioner as head of the ICAC,[28] there would be many things that he could do, or attempt to do, whether directly or indirectly, and whether administratively or otherwise, to frustrate or delay the investigation, or to otherwise interfere with the investigation or affect its outcome, if not to bring about its termination altogether. He may or may not be successful in his attempt. But that is not of relevant importance. The contrary position, with respect, is unrealistic and untenable. 36. In neither case, in the discussion above, is it incumbent upon the Chief Executive or the Commissioner to formally invoke any legal power to terminate the investigation as such. 37. Mr Tse argued that there are checks and balances on what the Commissioner can or cannot do regarding an investigation. In particular, there is the independent Operations Review Committee which, in short, monitors the investigation works of the ICAC and offers advice in respect of the same, and there is also the Secretary for Justice whose legal advice whether to prosecute the ICAC has to seek upon the conclusion of an investigation. 38. With respect, this argument confuses a tendency to pervert the course of justice with a certainty that the course of justice will be perverted. Counsel’s argument would mean that threatening a single justice of appeal sitting in an appeal does not amount to the offence of perverting the course of justice as he sits in a collegiate court, or that bribing one juror is no offence as a jury comprises seven or more jurors. This argument also overlooks the fact that the offence is committed not only if there is a tendency that the proceedings are terminated as a result of the prohibited act, but also where there is a tendency that they are otherwise interfered with or affected as a consequence. Answer to Question 1 39. For all these reasons, in my view, Question 1 must be answered in the negative, insofar as the present type of case is concerned. Depending on the facts, however, what is true in relation to the Chief Executive and the Commissioner may or may not be true with other office-holders. The answer in each case must depend on the facts. 40. The above answer in the present appeal effectively removes the underlying premise of the legal questions argued before the trial judge and the Court of Appeal, that is, certified Questions 2 to 4. They are simply irrelevant to the question of whether the appellant’s acts had the tendency to pervert the course of justice. Mr Tse’s further arguments 41. Mr Tse argued that the above analysis would only hold true if his client were charged with attempting to pervert the course of justice by interfering with the ongoing investigation. However, according to the particulars of the charge, the offence charged was to attempt to pervert the course of justice by stopping the investigation. Without a legal power on the part of the Chief Executive or the Commissioner to do so, the charge cannot stand. 42. I do not accept this argument. As has been pointed out by this court, whilst the particulars of a charge are undoubtedly important, the overriding test in charging an offence in Hong Kong is one of fair notice.[29] 43. In the present case, what the appellant was charged with was the common law offence of attempting to pervert the course of justice, which is, of course, not limited to the termination of the relevant investigation or curial proceedings. It is true that the particulars of the charge referred to the appellant by his emails and letter seeking to influence the Chief Executive and/or the Commissioner to terminate the ongoing investigation. It is also true that the gravamen of the complaint against him was the various threatening and intimidating matters he wrote in the emails and the letter and the ultimate goal that he sought to achieve, that is, the termination of the investigation. However, whilst the termination of the investigation was the appellant’s goal, what he attempted to achieve via his threats and intimidations must also include the Chief Executive’s and the Commissioner’s interfering with, delaying or otherwise favourably affecting the investigation or its outcome. And all this would equally amount to an attempt to pervert the course of justice with which he was charged. This could not have been lost on the appellant or his legal advisers. In my view, there is no question of their not having received fair notice of it. 44. This brings me to another point raised by Mr Tse, that is, that throughout before the trial judge and the Court of Appeal, the prosecution never raised the argument that apart from the strict legal powers that the prosecution said the Chief Executive and the Commissioner possess to terminate an ongoing investigation, a tendency to pervert the course of justice could otherwise be established. It was only at the leave stage before the Appeal Committee that for the first time it was argued that it was not necessary for the prosecution to establish such legal powers. 45. In my view, counsel’s argument had no significance, as he was not running any fair trial argument or abuse argument such that the prosecution should not be allowed to run this argument before us. 46. Nor has counsel objected to the Appeal Committee’s certifying Question 1 (referring not just to the Chief Executive and the Commissioner stopping the investigation but also interfering with it) and putting it as a prior question to Questions 2 to 4, when granting leave to appeal on that basis. Indeed, in the written case, the appellant seems to accept that the court should have regard not just to the legal position but “should extend it to include practical terms”.[30] In any event, the Court is not confined to the questions formulated by the parties but may itself raise issues necessary for the effective determination of the appeal, provided of course that no procedural unfairness is involved. 47. One last argument of Mr Tse was that leaving aside the Chief Executive’s and the Commissioner’s (supposed) legal powers to terminate the investigation, there was no or insufficient evidence adduced by the prosecution at trial to prove how they could otherwise interfere with the investigation. 48. Mr Tse was right in saying that the prosecution did not adduce any specific evidence to prove how the Chief Executive or the Commissioner could interfere with the investigation. However, for the reasons explained above, I do not think any such specific evidence was required. Given the unique and head positions that they held, both the Chief Executive and the Commissioner were obviously in a position to interfere with or affect the investigation or its outcome in a way favourable to the appellant (if they wanted to or were forced to). Disposition 49. In conclusion, I answer Question 1 in the negative (insofar as the present type of case is concerned). Questions 2 to 4 therefore do not arise, and I do not find it necessary or desirable to express any views on them in these reasons for dismissing the appeal. I wish, however, to make it clear that by not addressing the issues in these other Questions, I should not be taken as in any way agreeing with or endorsing the analysis of the lower courts on them. Mr Justice Gleeson NPJ: 50. I agree with the Judgment of Mr Justice Cheung PJ. Mr Joseph Tse SC, Ms Doris Ho and Mr Byron Tsang, instructed by Ledwin Au & Co, for the appellant Mr Johnny Mok SC, on fiat, and Mr Jonathan Lin, SPP, of the Department of Justice, for the respondent [1] Cap 201. [2] Cap 221. [3] Per the certified translation. The original Chinese reads: “從政治、全局高度考慮問題，緊急制止對我的無理迫害，避免在社會引起巨大震憾！” [4] “請他的手下慎之又慎，否則將引爆政治炸彈！” [5] “立刻向中外媒體及中央人民政府公布包含驚天內幕的《敦促梁振英辭職書》，與恩將仇報者同歸於盡！” [6] “請您立即採取果斷措施，制止對 [我] 的迫害！” [7] “迅速指示廉政公署停止不合理的調查。” [8] HCCC 561/2013. [9] DCCC 819/2013. [10] [2018] 2 HKLRD 967. [11] I will refer to this Ordinance as the ICAC Ordinance. [12] [2018] HKCA 281. [13] Para 154(II) of the main judgment. [14] [2018] HKCFA 48. [15] HKSAR v Wong Chi Wai (2013) 16 HKCFAR 539, para 30, quoting from R v Vreones [1891] 1 QB 360, 369. [16] Ibid,para 30. [17] Ibid, para 31. [18] HKSAR v Egan (2010) 13 HKCFAR 314, para 126. [19] Egan, para 127. [20] Articles 48 and 57 of the Basic Law; sections 5, 8, 9, 11, and 12 of the ICAC Ordinance; section 39(1) of the Interpretation and General Clauses Ordinance (Cap 1); and the English common law on the UK Commissioner of Police’s operational discretion. [21] [2008] 3 HKLRD 213. [22] Para 23. [23] Para 24. [24] Article 43(1) of the Basic Law. [25] Section 5(1) of the ICAC Ordinance. [26] Article 57 of the Basic Law; section 5(1) and (2) of the ICAC Ordinance. [27] See Wong Chi Wai, para 31(a). [28] See para 31 fn 25 above. Note also the powers vested in the Commissioner under section 12 of the ICAC Ordinance. [29] HKSAR v Gammon Construction Ltd (2015) 18 HKCFAR 110, paras 42 to 43; HKSAR v Ng Yee Man Yvonne (2015) 18 HKCFAR 405, para 21. [30] Appellant’s written case, para 49.