Underworld don Dawood Ibrahim had married a Bollywood actress and has a secret son from the relationship, a former police officer has revealed in his long-anticipated book, reports said.

Neeraj Kumar, who has earlier served as Delhi police commissioner and CBI deputy director, disclosed the details of the investigation he had carried out in connection with the 1993 Mumbai serial blasts in his book titled "Dial D for Don" that will be launched on Saturday.

In the upcoming book, Kumar reveals that Dawood was in a secret relationship with a Bollywood actress and that the duo has a son. The son, who lives in Bengaluru, is reportedly being brought up by the film star's sister.

The former cop also recounts three conversations with the underworld don, in which the latter pleaded his innocence in the Mumbai blasts and said that he met Dawood Taklya only to settle disputes between Tiger Memon and the criminal syndicate of Haji Ahmed, Salim Sarang and Aslam Patni, said reports.

Kumar, who is a 1976 batch retired IPS officer of Union Territories cadre, is currently serving as the chief adviser to BCCI's Anti-Corruption and Security Unit (ACSU). He has also closely worked with organisations such as the FBI and the New Scotland Yard.