Union Environment Minister Jairam Ramesh flew to Sariska reserve in Rajasthan on Wednesday after a tiger was suspected to have been poisoned to death by local people.
The vets in the tiger reserve found after an autopsy on the carcass that the three-and-a-half-year old big cat, which was translocated from Ranathambhore National Park in 2008, had been poisoned to death.
Police suspect that the predator was killed by the villagers around the reserve.
The autopsy report was different from an earlier claim that the tiger had died in a territorial fight.
The post mortem report did not say about any mark of injury on the dead animal.
Two forest officials were suspended on Tuesday on charges of dereliction of duty.
Nearly six years ago Sariska lost all its tiger population due to poaching.
Later,Prime Minster Manmohan Singh convened a meeting of the National Board on Wildlife, which suggested relocation of five tigers to Sariska from Ranthambore National Park in 2008.