Myanmar’s military government has freed a prominent former student activist, Ko Ko Gyi, more than 13 years after he was jailed, radio broadcasts from outside the country reported Thursday.

Radio Free Asia, funded by the U.S. government, reported his release and interviewed him. He was also interviewed by the Norway-based Democratic Voice of Burma.

Ko Ko Gyi was deputy chairman of the All Burma Federation of Students Union, which spearheaded mass pro-democracy demonstrations in 1988.

The demonstrations, aimed at ending more than two decades of military rule, were violently suppressed by the military, which reasserted control and still runs the country.

Ko Ko Gyi said in the phone interview with Radio Free Asia that he was arrested several times and was sentenced to 20 years in prison in 1991.

Ko Ko Gyi said he was moved from Thayet prison in central Myanmar to Yangon’s notorious Insein Prison on March 10, where he was released Wednesday afternoon.

Asked about his health, Ko Ko Gyi said he was generally well but needed to undergo a thorough medical checkup.

Ko Ko Gyi said he had spent 13 years and four months in prison and had a lot to catch up on before he could decide his future plans.

Asked how he was treated in prison, Ko Ko Gyi said he did not want “to discuss the past.”

Another former student activist, Zaw Min, was released from prison early this month after 14 years in prison. The most prominent former student leader, Min Ko Naing, was freed last November after spending nearly 16 years in prison.

Although the junta periodically releases political prisoners, more than 1,300 are estimated to still remain in its jails, including many who are old and in poor health. The country’s most prominent political prisoner is Nobel Peace Prize laureate Aung San Suu Kyi, head of the opposition National League for Democracy. She has been under house arrest in Yangon since being detained in May 2003.