Complex sentence: He is also being sought by two Taiwanese men (who want the Hawkins tape) and by the police, who are aware of Nadia's cassette and that it incriminates a prominent gangster, but unaware the gangster is also a senior officer.
Split into simpler sentences: He is also being sought by two Taiwanese men (who want the Hawkins tape) and by the police. The police are aware of Nadia's cassette and that it incriminates a prominent gangster, but unaware of the gangster's identify and that he's also a senior officer.