Facing 21 cases under the Wildlife Protection Act in seven states, the 59-year-old was accused of killing scores of tigers, leopards and other wild animals and smuggling their body parts.

“It is an end of a dark chapter in wildlife. He was a potent danger to wildlife. It is believed Chand was carrying out his activities from the jail. His acquittal in a number of cases was worrisome,” said standing counsel of Animal Welfare Board of India, Dr Mahendra Singh Kachhawa.

In 2006, Chand apparently admitted to selling 470 tiger skins and 2,130 leopard skins to just four clients from Nepal and Tibet, according to an agency report.

Chand was brought to a court in Alwar from Delhi’s Tihar jail for a court hearing on March 14. Soon after the hearing, he complained of unease and was admitted to Alwar district hospital from where he was referred to the SMS hospital the same day.

The next hearing in the case was scheduled on Tuesday, Chand’s counsel Ashok Sharma said.

“Tumours were detected in his lungs, brain and spinal cord. The cancer was in its last stage,” said a spokesperson at the Sawai Man Singh hospital of Jaipur.

Belonging to the Gihara tribe of Thanagazi area of Alwar district, Chand was initiated into poaching and smuggling by his grandfather Pannalal at the age of 12. He learnt the tricks of the trade fast and developed a strong international network, too.

He was in jail since 2005 when the Delhi police arrested him. Chand had amassed huge properties in Delhi and other states.