Lawyers and other persons claiming to represent indicted Serbian war crimes suspect Zeljko Raznatovic, who was assassinated in Belgrade Saturday, approached the U.N. tribunal in The Hague several times in 1998 and 1999, tribunal spokesman Paul Risley said today.

But, Risley said, "none of the contacts resulted in actual discussions with the office of the prosecutor regarding the surrender of Arkan," the nom de guerre by which Raznatovic was best known. Arkan was gunned down along with two of his bodyguards in a Belgrade hotel lobby Saturday, and speculation on the motive of the killers has centered on negotiations Arkan reportedly was having with the U.N. war crimes court.

According to the most prevalent theory, Arkan was killed by elements close to Yugoslav President Slobodan Milosevic--who was indicted by the tribunal last year on war crimes charges connected with the Kosovo conflict--because he was threatening to give prosecutors information about Milosevic in exchange for leniency in the case against him.

Senior NATO officials said there is still doubt about whether Arkan was killed by Milosevic allies or by a rival criminal gang, but they said the professional nature of the killing and the fact that Arkan seemed to trust his attackers suggests that Milosevic associates may have been behind the attack.

No evidence that he seriously engaged in negotiations with the war crimes tribunal has yet come to light. He was indicted secretly in 1997 on charges of crimes against humanity for his role in leading a paramilitary organization known as the Tigers during the 1991-95 factional wars in Croatia and Bosnia.

The indictment was revealed by the tribunal in March 1999, at the outset of the NATO air campaign against Yugoslavia, but its contents remain sealed. Chief prosecutor Carla Del Ponte said in a statement Monday that the tribunal's efforts to prosecute other suspected war criminals precluded the release of information in the Arkan indictment.

Risley said today that Del Ponte believes the approaches to the tribunal on Arkan's behalf, which Risley would not describe in number or detail, probably were aimed at "getting as much information as possible about the charges under seal rather than a genuine attempt by Arkan to surrender himself."

One current and one former U.S. official familiar with Balkan war crimes investigations said today they are skeptical that Arkan was shopping for a deal with the tribunal. They said Arkan had such an egregious and well-known record of brutality and atrocities in three war zones--Croatia, Bosnia, and last year in Kosovo--that he would have had very little to negotiate with tribunal prosecutors other than the severity of a prison sentence.

Correspondent William Drozdiak in Brussels contributed to this report.