Former Khmer Rouge tribunal defendant Ieng Thirith died at about 10:30am in Pailin province on Saturday at the age of 83, the court has announced.

The cause of death was not immediately clear, according to a court spokesman,

Thirith – who was married to former Khmer Rouge Minister of Foreign Affairs Ieng Sary, who died in 2013 – served as minister of social action under the regime, and had been severed from the court proceedings in 2012 after being diagnosed with progressive dementia.

The court’s announcement noted that Thirith had been indicted in 2010 “on charges of genocide, crimes against humanity and grave breaches of the Geneva Conventions of 1949”.

According to a tribunal biography, Thirith graduated from the Lycée Sisowath before travelling to France to study Shakespeare at the Sorbonne, ultimately becoming the first Cambodian to earn a degree in English literature. She returned to Cambodia in the late 1950s and worked as a professor and school director before joining the Khmer Rouge.

She allegedly remained a member of the regime long after its ouster in January 1979, only leaving in 1996 when her husband defected and was granted royal amnesty.