LUCKNOW: Indian police shot dead one of the country's most wanted gangsters Friday just a day after his dramatic arrest, sparking accusations of a staged extra-judicial killing.

Officials said Vikas Dubey, detained for the killing of eight police officers, was shot as he tried to escape a police vehicle while being driven to his home city in the northern state of Uttar Pradesh.

Within hours of TV stations carrying images of his bloodstained body lying in a hospital, rights lawyers and activists alleged that police had killed Dubey to prevent him revealing his connections with powerful people.

"This is the most blatant case of extra-judicial killing. Dubey was a gangster terrorist who may have deserved to die. But (Uttar Pradesh) police have killed him to shut his mouth," Supreme Court lawyer Prashant Bhushan wrote on Twitter.

"Will we allow police to kill anyone without a court trial?" Utsav Bains, another Supreme Court lawyer, added.

Senior opposition Congress party leader Priyanka Gandhi said the people "protecting" Dubey were still free.

Dubey, aged about 50, was accused in more than 60 murders, attempted murders and other cases. He was said to have shot dead an Uttar Pradesh state minister inside a police station in 2001.