(CNN) -- A judge has ordered an independent inquiry into whether war-crimes prosecutors at The Hague may have intimidated and/or pressured witnesses testifying in the continuing trial of a Serbian politician accused of war crimes.
Presiding Judge Jean-Claude Antonetti announced he would appoint an amicus curiae (friend of the court) to look into the charges, according to documents posted on the website of the International Criminal Tribunal for the former Yugoslavia.
The U.N. court deals with war crimes that occurred during the conflicts in the Balkans in the 1990s.
Antonetti ordered the inquiry on June 29, but it received scant attention until Wednesday, when a reporter asked about it at The Hague.
The inquiry cites former Chief Prosecutor Carla Del Ponte as well as prosecutors Hildegard Urtz-Retzlaff and Daniel Saxon. Del Ponte stepped down from the job at the end of 2007 and is now Switzerland's ambassador to Argentina.
"She's only mentioned because she's the former head of the office, but the allegations are aimed at the investigators and lawyers who worked for her," said Frederick Swinnen, special assistant to the current prosecutor at The Hague, in a telephone interview Wednesday with CNN.
A man who answered the telephone at the Swiss Embassy in Buenos Aires said Del Ponte was on vacation and not available.
The allegations concern testimony in the continuing trial of Vojislav Seselj, a former political ally of former Yugoslav President Slobodan Milosevic, who died in 2006 while on trial at The Hague.
Seselj first made similar complaints three years ago, Swinnen said. He noted that the defendant has himself been convicted for contempt of court.
The friend of the court has not yet been appointed, he said Wednesday. "There are several candidates; it's still at a preliminary stage," he said, adding that he did not expect the inquiry to find any malfeasance.
"Our view is our staff has acted in a professional way and within the rules," he said. "Once an amicus curiae is appointed, we will work with him and assist him in his task."
The inquiry was initiated after a number of witnesses complained "that they had been allegedly intimidated or pressured" by prosecutors, said Swinnen.
"The chamber obviously took these allegations very seriously and decided that it would be wrong to leave any space for doubt arising either on the protection of the rights of the accused or on the investigation techniques by members of OTP [Office of the Prosecutor]," said Christian Chartier, acting spokesman for registry and chambers, in a statement on the court's website.
The friend of the court is to report back to the chamber within six months whether there are sufficient grounds to start contempt proceedings against investigators for the prosecution, he said.
One witness said he and his family "were subjected to tremendous pressure by the prosecution," including 30 to 50 telephone calls per say from the prosecution, the judge wrote.
Another said prosecutors told him that, "if he testified, after that he could go to America, that he would get a good salary and would get money."
Complaining statements also "mention sleep deprivation during interviews, psychological pressuring, an instance of blackmail (the investigators offered relocation in exchange for the testimony they hoped to obtain), threats (one, for example, about preparing an indictment against a witness if he refused to testify), or even illegal payments of money," the judge wrote.
The prosecution said it "considers these allegations to be utterly devoid of factual basis."