A 34-year-old political prisoner in military-ruled Myanmar has died in custody, where he had been tortured and suffered from malaria, Amnesty International said on Tuesday.
The London-based rights group said Ko Thet Win Aung had been imprisoned since 1998 for organising peaceful, small-scale student protests calling for improvements to the education system and the release of political prisoners.
It urged the military that has run what used to be Burma for four decades to "initiate a prompt, independent investigation into the causes of Ko Thet Win Aung's death and to make the findings public".
Relatives confirmed the death in Mandalay Prison, where he was serving a 59-year sentence.
"Prison authorities informed us yesterday (Monday) about his death. They did not give us any further information," his brother, Ko Thein Tan, told Reuters.
"His health was in very bad condition. He contracted malaria in prison and developed some nervous troubles too and became paraplegic about one year before he died," he added.
Ko Thet Win Aung, the youngest of six siblings, was a brother of Ko Pyone Cho, a prominent student leader in a 1988 pro-democracy uprising in which several thousand people were killed.
"My father and Ko Pyone Cho visited Thet Win Aung in Mandalay Prison on September 27.
Three days later, on September 30, Ko Pyone Cho was arrested in Yangon," Thein Tan said.
Ko Pyone Cho, first imprisoned for more than 14 years after the army crushed the 1988 uprising, was among five former student protest leaders arrested last month and accused of involvement in "terrorist acts".
Thet Win Aung took part in the uprising as a high school student in 1988. He was arrested first for his political activities in 1990 and released the following year. He was last arrested in 1998 and jailed.
Amnesty said the number of deaths of political and normal detainees were on the increase in Myanmar and that already poor prison conditions had deteriorated further in 2006.
The International Red Cross suspended its prison visit programmes at the start of the year after the military junta said representatives had to be accompanied officials from local aid organisations.
According to the United Nations, Myanmar has more than 1,100 political prisoners. Nobel peace laureate Aung San Suu Kyi, who has been under house arrest for 10 of the last 17 years, is the best known.