Mumbai: After 18 hours of autopsy on businessman Mansukh Hiren - whose body was found in Thane Creek marshes - his deeply saddened family accepted his mortal remains for the last rites on Saturday.

With no visible injury marks on Hiren's body, his family and friends have dismissed the 'suicide by drowning' as he was an expert swimmer, besides eyewitnesses who have questioned why his mouth was gagged with 5-6 handkerchiefs.

The 48-year-old came into the limelight after his stolen SUV was abandoned near residence of Reliance Industries Head, Mukesh Ambani on February 25.

The police found 20 gelatin sticks in it besides a purported threat letter to the Ambani family. 10 days later, Hiren's body was fished out of the wetlands in Thane Creek on Friday stoking a massive political row.

The state government late on Friday handed over the probe to the Anti Terrorist Squad (ATS) which has started its investigations.

Deputy Commissioner of Police (Zone I) Avinash Ambure said that the autopsy report was shared with the family, but declined further details as the probe is underway.

Meanwhile, a letter claimed to be penned by Hiren on March 2 to Chief Minister Uddhav Thackeray, Home Minister Anil Deshmukh, Mumbai Police Commissioner Param Bir Singh, Thane Police Commissioner Vivek Phansalkar, spoke of police harassment after the recovery of his SUV with the gelatin sticks and threat letter.

Police are also trying to verify Hiren's wife Vimala's statement that on Thursday he was summoned by one officer from Kandivali Crime Branch who asked him to meet him near the Thane Creek.

Meanwhile, the BJP in Maharashtra has demanded that the case should be handed over to the NIA.

Many leaders from BJP met Hiren's family members and a large number of people turned up for Hiren's funeral held on Saturday.

(With inputs from IANS)