The mass grave was discovered after Ermin Lipovic, a criminal inspector for the Bihac police and an amateur climber and caver, descended into Bezdan pit with a photo and video camera in August 1997. He photographed and videotaped both the descent into the cave shaft and features of the cave floor. It was clear from both the photographs and the video footage that there were numerous human skeletal remains and remnants of clothing on the cave floor.

In September and October 1997, among the layers of garbage in the pit, the remains of 83 bodies were discovered. Sixty-five of them have been identified. The process of exhumation was halted several times due to the discovery of unexploded devices under the garbage and the bodies. All the victims were male and between 14 and 65 years of age. The most common cause of death was multiple gunshots. 

The victims were Bosniaks from Ljutocka Valley who were held at the IMT Tractor Service detention centre in the village of Ripac in July 1992 by the Bosnian Serb Army. According to witness statements, the murders were carried out by the 15th Light Infantry Brigade, members of military police platoons and local militia fighters. The victims were taken there in groups, executed and thrown into the pit.

The site is now marked with a plaque commemorating the victims who were killed in the summer of 1992, while the pit has been partially closed with a memorial monument.

Zeljko Stanarevic, a former military police officer with the 15th Light Infantry Brigade of the Bosnian Serb Army, was jailed for 13 years by the Bosnian state court for crimes committed in the Bihac area. The court found him guilty of participating in the murders of at least ten Bosniak civilians near the village of Hrgar. According to the verdict, Stanarevic and six other Bosnian Serb Army soldiers went the tractor workshop in Ripac where the civilians had been detained between June 24 and the first half of July 1992. 

At least ten of the civilians were then singled out, tied up and transported by truck to Hrgar and killed.

Another former Bosnian Serb Army soldier, Sasa Curguz, was also convicted in Bosnia and Herzegovina of involvement in the crime at Mount Hrgar and sentenced to 14 years in prison. Curguz was found guilty of participating in the murders of at least 11 prisoners from the village of Ripac and of inhumanely treating Bosniak detainees. According to the verdict, Curguz and six other Bosnian Serb soldiers arrived at the IMT Tractor Service in Ripac, where at least 55 captured Bosniak men were being held. The prisoners were put on a truck and transported to the edge of the Bezdan pit. One soldier immediately killed at least three prisoners, then two others threw the bodies into the pit, on the instructions of Curguz, who also personally killed several prisoners.

Former Bosnian Serb Army soldier Dragan Dopudja went on trial in Belgrade in 2021 for allegedly killing at least four prisoners near the village of Hrgar, whose remains were later found in the Bezdan pit.

In 2020, Interpol issued a ‘red notice’ calling for the arrest of Gojko Borjan, who is also suspected of committing war crimes at Mount Hrgar.

The case against Nenad Bubalo, a former Bosnian Serb Army military policeman accused of participating in the murders of at least five civilians at Mount Hrgar whose bodies were thrown into the Bezdan Pit, was closed in 2021 after he died.