Valmiki Tiger Reserve (VTR) has lost yet another big cat to poachers.

A fortnight after the carcass of a male tiger was recovered, forest officials on Tuesday found that of a tigress in Ganauli range around 290km northwest of Patna.

Forest officials claimed that a gang of poachers poisoned both big cats around the same time.

The tigress' carcass was found after the kingpin of the poachers' gang was arrested on Sunday, said S.S. Choudhary, additional principal chief conservator of forests (wildlife)-cum-chief wildlife warden of Bihar. "It is not a fresh killing. What we have recovered is the carcass of a tigress that died around three months back," he said.

"Hari Guru, the gang's kingpin, was arrested in Nepal on Sunday based on information gathered from other members of his gang who were arrested earlier," Choudhary told The Telegraph. "The poachers had poisoned water bodies and carcasses of few animals at eight locations in VTR. They succeeded in killing four tigers."

On February 20, officials at the reserve had found the carcass of a male tiger, which had also died of poisoning.

"The female tiger's body was found in Ganauli range this morning," said R.B. Singh, conservator of forest-cum-director, VTR. "The tigress is believed to have been poisoned around three months back. We are awaiting findings of the post-mortem report."

Bihar's lone tiger reserve has lately become the hotbed for tiger poaching.

Officials from New Delhi-based Wildlife Crime Control Bureau and the VTR had arrested two poachers on January 19. Complete skin and bones of two fully-grown tigers were recovered from their possession. After interrogating the duo, VTR officials nabbed another 10 poachers in Madanpur range on February 6. The criminals hailed from West Champaran in Bihar and Kushinagar in neighbouring Uttar Pradesh and Nepal. Forest officials said that the kingpin, Hari Guru, is from Ganauli.

Wildlife protection experts said tiger reserves in the border areas are more prone to poaching activities.

"Tiger reserves like VTR or Buxa Tiger Reserve in Bengal that are located on the national border are prone to poaching because of demand from international markets," said Shekhar Kumar Neeraj, India head of wildlife trade monitoring network Traffic. "Almost all tiger reserves and wildlife sanctuaries in India face manpower crunch. The same is the case with VTR. It is thus imperative that VTR and other such reserves be given special status so that adequate security can be provided."