[JURIST] Defense lawyers for Nuon Chea [case materials, PDF], a former leader of Cambodia’s Khmer Rouge regime [BBC backgrounder; JURIST news archive] filed a lawsuit Monday against Prime Minister Hun Sen [BBC backgrounder] for interfering with the UN-backed war crimes tribunal. Chea’s lawyers accused the prime minister of criminally conspiring to block some of the defense witnesses from testifying [Reuters report] and consequently interfering with Chea’s right to a fair trial. Chea, along with three other defendants, will go on trial next month [JURIST report] on charges of crimes against humanity, genocide, religious persecution, homicide and torture in the Extraordinary Chambers in the Courts of Cambodia (ECCC) [official website]. The seven-year old tribunal is expected to spend about $150 million by the end of the year and has only issued one sentence since its creation. Former Judge Siegried Blunk recently resigned because of implications of a lack of impartiality [JURIST report] made by the Cambodian foreign minister.

Last week, UN Under-Secretary General for Legal Affairs Patricia O’Brien urged the Cambodian government to refrain from interfering [JURIST report] with the ECCC’s work. In a meeting with Cambodia’s Deputy Prime Minister Sok An to discuss recent developments at the tribunal, O’Brien expressed concern and reiterated the call to respect the integrity and independence of the tribunal. Last month, the ECCC ordered the trials of four alleged Khmer Rouge leaders be split into a series of smaller trials [JURIST report] to allow the tribunal to deliberate more quickly in the case. A week earlier, the ECCC concluded three days of hearings [JURIST report] aimed at determining whether two of the four Khmer Rouge leaders were fit enough to stand trial on accusations of genocide and other war crimes. The four leaders include Chea, who was Pol Pot’s second-in-command and the group’s chief ideologist, former head of state Khieu Samphan, ex-foreign minister Ieng Sary, and his wife, Leng Thirith [case profiles, PDF], who served as minister for social affairs. All four have pleaded not guilty to charges including crimes against humanity, war crimes, genocide, religious persecution, homicide and torture.