It was supposed to be a model for international justice and national reconciliation: a U.N.-backed tribunal to hold trials on one of the 20th century's grimmest chapters _ the Khmer Rouge's murderous 1970s regime in Cambodia.
Eight years after its creation, however, the multinational panel is riven by suspicion, infighting and angry resignations over whether to try more Khmer Rouge defendants on war crimes charges, in addition to the jailer already convicted and four top officials scheduled for trial June 27.
Critics fear the panel is caving to pressure from Cambodia's strongman prime minister _ himself a former Khmer Rouge cadre _ to quash any further indictments, or that the United Nations' resolve to continue the trials may be waning.
The tussle raises questions about whether the panel can find full justice for the estimated 1.7 million people who were killed, starved, worked to death or died of disease in the "Killing Fields" of the Khmer Rouge's savage 1975-1979 rule.
"The integrity of the (tribunal) hangs in the balance," warned former U.S. war crimes ambassador David Scheffer, who helped establish the court.
One of five panel employees who recently quit in frustration, London-based researcher Stephen Heder, chastised investigative judges in his resignation letter for what he described as closing the case on the additional suspects "effectively without investigation."
Heder also cited the "toxic atmosphere of mutual distrust" at what he called "a professionally dysfunctional office" of the tribunal's investigating judges, according to a copy of the letter obtained this week by The Associated Press.
The United Nations weighed in Tuesday, with the chief spokesman for Secretary General Ban Ki-moon strongly supporting the panel and its impartiality.
Prime Minister Hun Sen's government sought the United Nations' help in the late 1990s to create the tribunal. But he didn't want a fully international court, like for the former Yugoslavia.
Despite misgivings from negotiators, the final agreement in 2003 set up a hybrid system, with Cambodian and international judges and prosecutors working with Cambodian and international laws, under French-style rules.
"I did not want ... the U.N. emblem to be given to an entity that did not, shall we say, represent the highest international standards," Hans Corell, the chief U.N. negotiator at the time, told AP. "But of course what we predicted seems to have developed into the problem that we were concerned would occur."
Prosecutors have compiled substantial evidence for so-called Cases 003 and 004, which include two top military commanders who also were top officials in Cambodia's post-Khmer Rouge military, according to confidential court documents obtained by AP. The documents allege both took part in purges that resulted in tens of thousands of deaths.
The government, however, has openly stonewalled. Hun Sen told Ban last year that new cases would "not be allowed."
He has warned that new cases could spark renewed civil war, though his opposition likely stems from the many Khmer Rouge officials, like himself, who are now in government and who fear investigators could dredge up new evidence of war crimes.
"The Cambodian government has been forthright all along that there would be no new cases," said Anne Heindel, legal adviser to the Documentation Center of Cambodia, which researches the Khmer Rouge. "It's the failure of the United Nations to act that's been surprising."
Scrutiny recently has focused on the two investigating judges who, under the French-style rules, are primarily responsible pretrial investigations. Separate seven-judge panels try the cases.
Many had hoped that German investigating judge Siegfried Blunk would pursue the new cases despite objections of his Cambodian counterpart.
Instead, the judges' office has made a series of controversial rulings that many observers say are without legal basis and appear intended to pre-empt at least one of the cases.
British co-prosecutor Andrew Cayley has fought the rulings and released new details about the investigation, prompting a harsh rebuke from the judges, which Cayley slammed as "abusive," "unreasonable," "capricious," unprecedented."
Tensions among some court employees and U.N. legal advisers reached a boiling point last month when several employees sent an angry letter to Ban complaining about Blunk, according to two officials who have seen the letter, but asked to remain anonymous in order to discuss the court's internal matters. Blunk also sent a letter to Ban, though its contents are unclear.
At least five employees have resigned in protest over Blunk's actions, including Heder, a consultant who compiled extensive evidence about new suspects.
Blunk was also the focus of Cambodian rights activist Ou Virak, who complained that his conduct was "a matter of utmost concern" and suggested that the U.N. had acquiesced to Cambodia's government.
Blunk declined to answer questions from AP, but issued a statement through a court spokesman: "The co-investigating judges have worked independently from outside interference, and are resolved to defend their independence against all interference wherever it may come from."
The feud, and concerns about public perception, prompted officials from the court's main donors, which includes the United States, Australia and others, to intervene directly with Blunk and Cayley multiple times _ by phone and in person.
"I believe in the good faith in each of the good people that I'm talking with. They have very good reason for doing what they're doing," the current U.S. war crimes ambassador, Stephen Rapp, said in an interview with AP. "Reasonable people can disagree, but people need to see that this is an issue that this is being decided on the law not on the basis of political pressure."
Ban's chief spokesman Martin Nesirky in a statement released Tuesday denied speculation that it was pushing judges to close cases 003 and 004.
"The judges and prosecutors must be allowed to function free from external interference by the Royal Government of Cambodia, the United Nations, donor States, and civil society," he said. "It follows that the United Nations categorically rejects media speculation that we have instructed the (judges) to dismiss Case 003."
Clair Duffy, who monitors the tribunal for the Open Society Justice Initiative, said the damage the court has suffered could be mitigated by how the upcoming trial _ which includes the man who was second only to the infamous Pol Pot _ plays out, "and in particular whether it was able to withstand political pressure from the Cambodian government."
But the final judgment will rest with Cambodians and whether they embrace the court's decisions as model justice or political charade.
Associated Press writer Edith Lederer in New York contributed to this report from New York.