The FIR was registered on Tuesday after Delkar’s family members visited the Marine Drive police station and lodged a complaint, the official said.
The police registered the case under the charge of abetment to suicide and provisions of the Atrocities Act, the official said.
The police had recovered a 15-page suicide note from Delkar’s hotel room which was written on his letter head, the official said, adding the note mentioned some names.
Maharashtra Home Minister Anil Deshmukh on Tuesday announced that a Special Investigation Team (SIT) will probe the alleged suicide of Delkar.
Deshmukh said in the state Assembly that Delkar’s suicide note stated that the Union Territory’s administrator Praful Kheda Patel was harassing the MP.
Delkar’s wife and son met Chief Minister Uddhav Thackeray at the Vidhan Bhavan here on Tuesday.
Later, talking to reporters, his son Abhinav Delkar claimed Patel “left no stone unturned to humiliate” the deceased.