The chief prosecutor for the International Criminal Court said Thursday there are "serious suspicions" that the death of Libyan leader Moammar Gadhafi was a war crime.

Luis Moreno Ocampo told reporters after briefing the U.N. Security Council that he sent a letter to the head of the National Transitional Council asking what the government's plans are to investigate alleged war crimes by all parties, including the rebels.

The uprising against Gadhafi's 42-year rule erupted in February, quickly escalated into civil war, and ended in October with Gadhafi's capture and death in unclear circumstances. Witness accounts and video taken of the deposed dictator after his capture by rebel fighters show that he was beaten and abused by his captors, and there were strong indications he was killed in custody.

"The death of Moammar Gadhafi is one of the issues to be clarified _ what happened _ because there are serious suspicions that it was a war crime," Moreno Ocampo said.

He said what the ICC does on Gadhafi's death and other war crimes will depend on what Libya's interim government does because under the Rome statute that established the war crimes tribunal, the ICC only steps in if national authorities are unwilling or unable to act.

Moreno Ocampo said his office is working closely with Libyan authorities not only on Gadhafi's case but on those of his son, Seif al-Islam, and former intelligence chief, Abdullah al-Senoussi, who were captured and face ICC charges of crimes against captured for their roles in the uprising.

Libya's new leaders have said they will try Seif al-Islam at home even though they have yet to set up a strong court system. The ICC wants to be certain the government will be capable of putting on a fair trial for Seif al-Islam and al-Senoussi.

Moreno Ocampo said in an AP interview that the judges at the ICC have asked the National Transitional Council to inform them of their plans before Jan. 10. He said if the government challenges the ICC's jurisdiction, it will be up to the judges to decide where the two accused will be tried.

In the meantime, he said, his office is continuing its investigation.

"We are sure there were massive rapes, quite sure," Moreno Ocampo said. "We're trying to define who ordered them."

The Security Council referred incidents stemming from the Libyan uprising to the ICC and Moreno Ocampo said he promised the council that he would present his strategy for the continuing investigation of possible war crimes in his next report in May.

After Seif al-Islam's arrest, Moreno Ocampo flew to the Libyan capital late last month and met with government officials.

He said in an AP interview that the officials offered him the opportunity to meet Seif al-Islam. But he said he declined because Gadhafi's son would have needed to have a lawyer present and he had not asked to see the prosecutor.

Moreno Ocampo said the Libyan authorities told him it was "very important" to prosecute Seif al-Islam themselves for two reasons _ he is "the face of the old regime" and "they would like to show they can do better than with Moammar" and conduct a proper trial.

"If they can convince the (ICC) judges," Moreno Ocampo said, "we don't need to go and fight for a case."