March 3 (UPI) -- South Korea's first known transgender soldier was found dead in her apartment, more than a year after she was discharged from the country's military after gender reassignment.
Byun Hee-soo, 23, a former army sergeant in the South's military, became unreachable after Sunday, YTN and Yonhap reported Wednesday.
A local mental health center that provided regular support to Byun reportedly contacted authorities. Paramedics forcibly entered Byun's apartment in the central city of Cheongju.
The death has not yet been confirmed a suicide and Byun left no note behind, according to YTN.
Byun was a member of an army unit in northern Gyeonggi Province. In 2019, she returned from an overseas trip after undergoing gender reassignment surgery.
Byun's decision to return to the military as a woman came under official scrutiny. The army discharged the soldier in January 2020, citing an alleged "mental disorder."
Sources in the military have claimed the charge was related to Byun's reassignment surgery -- a statement that has been meet with public skepticism.
According to Yonhap, sources have said the "special security situation in South Korea, which is in the midst of a ceasefire with North Korea," does factor into the "issue of allowing a person who has undergone sex change to serve in the military."
Byun fought back with lawsuits and press conferences. The ex-officer asked the military to investigate the case after being dismissed in 2020, but authorities declined to accept requests.
Byun held a press conference at the time, vowing to "fight until the day I can remain to serve in the army."
The dismissed army sergeant also said she wanted to demonstrate her capability to protect her country, regardless of her gender identity.
In August, Byun filed a lawsuit against the country's army chief of staff at Daejeon District Court. A hearing on the case was scheduled for April 15, according to Yonhap.
Byun reportedly attempted to take her own life three months before health officials lost contact with her in February.