SEOUL, South Korea (AP) — South Korea’s first known transgender soldier, who protested the military’s decision last year to discharge her for undergoing gender reassignment surgery, was found dead at her home on Wednesday.

Shin Jeong-hwan, a fire department official in the central city of Cheongju, said rescue workers visited the home of Byun Hui-su after local mental health counselors reported that she had been out of contact for days.

The cause of death wasn’t immediately known. Shin said the decomposition of the body indicated she had been dead for days.

Byun, who had been a staff sergeant and tank driver, pleaded to be allowed to continue serving as a female soldier after the army discharged her in January 2020, triggering criticism by human rights advocates who saw the decision as discriminatory.

She said she had sex reassignment surgery in Thailand in November 2019 after suffering depression over her sexual identity for an extended period.

South Korea prohibits transgender people from joining the military and the army rejected Byun’s petition for reinstatement in July last year.

South Korea’s Defense Ministry spokesperson Moon Hong-sik during a briefing on Thursday expressed condolences over Byun’s death but said the military has no ongoing discussions about allowing transgender people to serve.