Khmer Rouge tribunal monitors say a conflict between two judges at the United Nations-backed court will hamper the pursuit of cases against former Khmer Rouge leaders.

Clair Duffy, a tribunal monitor for the Open Society Justice Initiative, said the rare public exchange highlights obstacles facing the court that need to be addressed by the broader international community.

The Cambodian investigating judge and his would-be international counterpart have argued publicly about opening investigations of defendants suspected of crimes against humanity under the communist regime of the late 1970s.

Reserve judge Laurent Kasper-Ansermet said earlier this week that the Cambodian investigating judge had prevented him from releasing important information about two cases in the court.

The Cambodian judge, You Bunleng, responded that Kasper-Ansermet had not yet been officially recognized by the Cambodian government as the international investigating judge, and that he lacked knowledge of the law.

Duffy said the Cambodian government had effectively stalled the official appointment of Kasper-Ansermet, who was nominated to replace German judge Siegfried Blunk. Blunk resigned citing government opposition to the two cases probing atrocities during the Khmer Rouge's four-year rule.

Both cases are strongly opposed by Prime Minister Hun Sen and other members of the government.

Duffy also criticized the U.N. and the donors for what she called their continued public silence in relation to these developments. She said that as a result of these developments, the two cases have not moved forward.

A U.N. spokesman said the organization is “aware of this development” but declined to comment further.