The state government had transferred the investigation to the CB-CID.Chennai: The post mortem report of 25-year-old Vignesh who died in police custody in Chennai last month has revealed there were 13 different bruises on his body. However, the exact cause of death is yet to be established as more reports are awaited. While police claim Vignesh died after suffering a seizure, the family and rights activists allege he was tortured. The post mortem report reveals contusions in several body parts, including his head, above the eyes, cheek and arms.Vignesh was arrested by the police on April 18 over alleged possession of marijuana. He died in police custody the next day.A sensational CCTV footage surfaced earlier this week that shows two cops chasing Vignesh as he stumbles and falls. The cops later arrest the man and beat him once with what appears to be a police baton.As the police personnel take him into custody, one cop is seen picking up something from the ground, which police sources claim was a knife Vignesh threw at them during the chase. NDTV cannot verify the authenticity of the tape.Two cops – an SI and a constable – have been suspended.The state government had transferred the investigation to the CB-CID.Chief Minister MK Stalin, who announced Rs 10 lakh rupees relief to the family, has promised a fair investigation into the case.The police claim, however, has been questioned by a human rights organisation that is keenly following the case.”This is just one camera. There are at least 15 cameras, but police have ensured nothing works. The man was tortured for three hours from 11 PM,” Henri Tiphangne, Director of People’s Watch a human rights organisation that has taken up this cause, told NDTV.Police sources say this is the video they had submitted to the court.Explaining the sequence of events, a member of the investigation team told NDTV, “This is the spot where Vignesh attempted to attack police throwing a knife. A frame-by-frame analysis of Vignesh’s body movement in the footage would indicate, the man used his hand to throw the knife without turning back and that’s when he lost balance and fell”.Police say Vignesh who was travelling in an auto was found in possession of cannabis (ganja) and he attempted to attack police with a knife and escape. It was then that he was chased and arrested, the police officials say. The next morning Vignesh, who used to ride horses on the beach for joy rides, reportedly suffered seizures and could not be saved despite medical help, they said.The family’s suspicion of foul play strengthened after the police reportedly donated Rs 1 lakh to them.