Yangon, Myanmar — A close ally of detained Myanmar democracy leader Aung San Suu Kyi died of leukemia on Monday, a party source told AFP, days after being released from junta custody on health grounds.

Zaw Myint Maung, 72, who spent around two decades in prison for defying Myanmar’s military, was a close confidante of Suu Kyi and a lynchpin of the National League for Democracy (NLD).

He was arrested following the military’s latest coup in 2021 and jailed for corruption. He was recently released on health grounds.

“We got confirmation of his death. It’s a big loss for us as he was one of our NLD vice-chairmen,” a senior party source told AFP, requesting anonymity to speak to the media.

The source said Zaw Myint Maung had died of leukemia.

“Although we were prepared we might lose him one day, we are sorry for losing him in this difficult situation. We have to move forward for democracy with the leaders we have.”

Zaw Myint Maung was detained along with other senior NLD figures following the 2021 coup that upended a 10-year experiment with democracy and returned the Southeast Asian nation to military rule.

In 1988 he led a doctors’ strike as part of huge pro-democracy uprisings that thrust Suu Kyi into the spotlight in Myanmar — then called Burma.

In 1989 he left his job in a university biochemistry department and joined the NLD.

The military later imprisoned him for around two decades for his activism.

After the generals enacted democratic reforms and the NLD won a landslide in the 2015 elections, he became the chief minister of the Mandalay region.

The year before the putsch Suu Kyi described him as a “real hardcore and a comrade who has been together with us since the very beginning [of our party].”

The 2021 coup sparked widespread armed opposition to military rule that the junta has failed to crush more than three years later.

Almost three million people have been forced from their homes by the conflict, according to the United Nations.