Myanmar has freed more than 3000 prisoners four weeks before a south-east Asia summit that will be attended by international and regional leaders including US President Barack Obama.

Among those released were prisoners of conscience and former military intelligence officers, including associates of former prime minister Khin Nyunt, who was freed from house arrest under a similar amnesty in 2012.

Free: Former brigadier general Thein Swe, who was serving a 152-year jail sentence. Credit:Reuters

Mynamar, which is also called Burma, has boosted its reformist credentials in the past by releasing political prisoners, often shortly before diplomatic meetings and summits.

President Thein Sein pardoned 3073 prisoners on Tuesday for the sake of "peace and stability" and the "rule of law," the government said in a website statement.