The Serbian defence ministry faces accusations of sexual discrimination, after a transgender veteran claimed she was forced to leave the army on the grounds that she harmed its reputation.
Rights group Egal said they filed a complaint with the state's commissioner for the protection of equality regarding the forced retirement of an army major who had recently initiated a sex-change process.
The group said the major, identified only as Helena, was ordered to quit the military by the defence ministry in October because her "psychiatric diagnosis" was detrimental to the good name of Serbia's armed forces.
"Though the military hospital told me I am fit for military service, someone in the defence ministry claims I threaten the reputation of the army," Egal quoted Helena as saying, Reuters reported.
Anti-homosexual views are rife in Serbia. Two-thirds of respondents to a survey four years ago said that they viewed homosexuality as a disease.
The aspiring EU member state has come under increasing pressure from Brussels to enhance equality and tolerance within its borders.
The first apparent results were witnessed in September last year, as the capital, Belgrade, hosted its first gay pride march for four years.
Egal spokeswoman Tamara Trikic told Reuters: "The legal position of transgender persons in Serbia is difficult. They encounter many problems related to legal matters such as securing new personal documents, employment, and health protection."
The commissioner for the protection of equality is due to report its findings on Helena's case within 90 days.