Salman Raduyev was found dead over the weekend in his cell in a high-security prison, where he was serving a life sentence for his role in taking more than 2000 people hostage in 1996.

'Given the widespread use of torture and ill-treatment in the Russian penitentiary system, there must be an independent investigation into the exact cause of death of Salman Raduyev,' the human rights organization said. Background

Salman Raduyev was accused of involvement in 1996 in the hostage-taking in the southern Russian republic of Dagestan, neighbouring the Chechen Republic, which left some eighty people dead. Two months after the incident he was severely wounded in an assassination attempt and had to undergo extensive plastic surgery abroad to rebuild his face. Raduyev was captured by Russian security forces in 2000. Shortly before his death, he was reportedly interrogated by the Russian authorities in connection with the extradition case against the Chechen politician, Akhmed Zakayev