The Army chief ordered a hunt of homosexual soldiers, committing human rights violations in the process, a civic group claims.
The hunt followed an earlier probe based on a video a soldier posted on social media showing him having sex with another soldier.
Army officials began the search after obtaining information about homosexual soldiers from the suspect, according to Lim Tae-hoon, the head of the Center for Military Human Rights Korea, Thursday.
The probe team targeted soldiers mentioned by others in the investigations, and also signed up for gay dating applications to find homosexual soldiers.
The hunt is based on the Military Criminal Act, under which sodomy is punishable by up to two years in jail.
The center took issue with the way the probe was conducted _ investigating individuals without evidence, forcing confessions and probing for irrelevant details.
"Simply subjecting individuals to an investigation based on their sexual identity is a discrimination and violation of human rights," Lim told a press conference in Seoul.
He said that according to testimonies, the probe team threatened to disclose the soldiers' sexual identity and asked in detail about their experiences of gay sex.
In some cases, the probe team is said to have "advised" the soldiers to "correct" their sexual identities.
Lim said this went against instructions within the military that ban identifying homosexual soldiers and asking them private questions such as about their sexual experiences and partners.
According to the center, 15 soldiers have fallen victim to the hunt and 40 to 50 are being investigated.
Based on reports the center has received, Lim said it suspected Army Chief of Staff Gen. Jang Jun-gyu ordered the hunt.
In response, the Army released a statement the same day, claiming it was only conducting a law-based investigation of those identified in the earlier probe.
"The probe is taking place, protecting the human rights and private information of the individuals and following legal procedures," the statement said.
"A soldier having sex with another male soldier is a violation of the law, and the military is criminalizing this as an indecent assault, considering the importance of discipline within the military."
While the center claims criminalizing gay sex is unconstitutional, the Army points out that the Constitutional Court recognized it as constitutional in 2002 and 2011.
"We are calling for Jang to resign and the Army to stop its illegal, inhumane probe," the center's Kim Hyun-nam said Friday. "We are also raising funds to provide legal assistance to the victims."