If you’re being interviewed by the Police and accused of committing a criminal offence, it’s your legal right not to incriminate yourself i.e. you can choose to remain silent and not to say anything that would suggest that you committed the offence.
According to the Criminal Procedure Code, you must tell the investigators what you know of the facts and circumstances of the case. However, you do not need to say anything that would tend to expose yourself to be liable for committing a criminal offence.
If you choose not to mention the facts regarding your defence early in your statement when you have the opportunity, it may be rejected by a Court at a trial later if it feels that your defence is less believable because it may have been only recently created.