Thet Win Aung (Photo Courtesy: 88 Generation Students)

A Burmese political prisoner advocacy group says Burma's military government is responsible for the death of a jailed student leader.

Media reports say the family of Thet Win Aung was notified of his death late Monday. No official cause of death was available, though his father says he may have died from a heart attack.

But the Assistance Association for Political Prisoners say they believe that Thet Win Aung was systematically killed by the government, as have more than 100 political prisoners who have died in Burmese prisons.

The group says Thet Win was tortured by military intelligence when he was arrested in 1998 for organizing student protests.

The groups says his 60-year prison sentence left him depressed and suffering from mental illness. They say he contracted malaria and was not given proper medical treatment.