The U.S., British and Saudi governments are investigating allegations that Libyan leader Moammar Gaddafi launched a plot to assassinate the ruler of Saudi Arabia and to destabilize the desert kingdom with the help of a prominent Muslim activist from Falls Church, according to an account in the New York Times that was backed up by an informed source with knowledge of the case.

Late last year Gaddafi renounced his program to develop Libyan weapons of mass destruction, in an apparent abandonment of years of pariah status, only after the alleged plot to kill Saudi Crown Prince Abdullah was exposed by a Libyan intelligence official and the Virginia-based activist, who were both alleged participants in the plot, said the Times and the informed source.

U.S., British and Saudi officials are investigating accounts of Gaddafi's supposed role in the plot that were given by Col. Mohamed Ismael, a Libyan intelligence official, and Abdurahman Alamoudi, a longtime Muslim activist who is facing federal charges of violating U.S. sanctions against doing business with Libya. Alamoudi allegedly received $340,000 in cash from Libyan officials, the source said.

Alamoudi offered his account of the alleged plot to U.S. prosecutors during plea negotiations over pending charges against him, the source said.

A source who had detailed knowledge of the events confirmed the Times account.

If the allegations of a Libyan plot to kill a foreign leader were confirmed, it would almost certainly cause the United Nations to reinstate sanctions against Libya that were lifted last year after Gaddafi renounced terrorism and acknowledged responsibility for the 1988 bombing of Pan Am 103 over Lockerbie, Scotland.

Alamoudi told U.S. officials he met twice with Gaddafi last year to talk about the plot, said the Times and the informed source. According to Alamoudi, Gaddafi said in the first meeting, "I want the crown prince killed either through assassination or through a coup." At another session a few months later, Gaddafi asked why he had not yet seen "heads flying" in the Saudi royal family, the Times and the source said.

Gaddafi and Abdullah feuded publicly at an Arab summit meeting in early 2003 -- shortly before the U.S. invasion of Iraq -- with Gaddafi telling the Saudi ruler at one point, "Your lies precede you, and your grave is in front of you."

Ismael was arrested in Egypt after a trip to Saudi Arabia during which, he said, he arranged for a group of Saudi men to look into attacking Abdullah, the Times and the source said. He confessed to the plot and was later transferred to Saudi Arabia, where he gave a full statement.

Last year Ismael and Alamoudi traveled to London and tried to recruit Saudi dissidents to join in the plot by distributing cash, the Times and the source said in summarizing the two men's statements.

Phone calls to attorneys for Alamoudi were not returned late last night. Alamoudi, founder of the American Muslim Council and other prominent Islamic groups, has denied the pending criminal charges.