A former leader of Myanmar's 2007 monk protests against the then-ruling junta said Tuesday he had been sentenced to six months in prison with hard labour on an immigration charge, in a case slammed by rights groups as politically motivated.
NyiNyiLwin, who was previously known by the clerical name Gambira, told AFP he was "so disappointed" with the ruling, relating to a 2013 incident when he travelled to neighbouring Thailand for treatment for trauma suffered during years as a political prisoner.
"I have been given a six month sentence with hard labour," he told AFP by telephone after the hearing at a court in the Maha Aung Myay area of Mandalay.
The former monk was among hundreds freed in amnesties in 2012 by the quasi-civilian government that replaced outright military rule a year earlier.
He had been serving a 68-year prison term for his prominent role in monk-led demonstrations five years earlier, known as the "Saffron Revolution", that were brutally crushed by the army.
Nyi Nyi Lwin has been repeatedly rearrested, while his family have raised concerns about his mental health, which suffered during years of detention.
Human Rights Watch slammed the latest case against him, saying he was subjected to physical and psychological torture following his initial arrest in 2007. 
HRW deputy Asia director Phil Robertson said the case "reeks of the ugly political prosecutions of discarded military juntas" and called for Myanmar's new government, under democracy champion Aung San Suu Kyi, to do more to help former political prisoners.
Her National League for Democracy (NLD) took power last month, riding a wave of huge popular support in a nation choked by repressive military rule for decades. 
Suu Kyi, who spent some 15 years under house arrest during the dark junta days, has in recent weeks overseen a push by her administration to pardon scores of political prisoners and quash charges against activists facing trial.
But that did not extend to NyiNyiLwin's case.
His sister LwinLwin Mar told AFP that the court found that he had crossed the border illegally when he travelled to Thailand for treatment. 
"He had been feeling unwell at that time and he needed treatment. I can't understand why the court has done this," she said.
©AFP