A Saudi sheik, the intended target of an international assassination plot, has called for an investigation into the events that led to the murder conspiracy conviction of former State Department official Walter Reed Martindale III.

Martindale, a Northern Virginia resident, was convicted by a U.S. District Court jury in Alexandria a week ago of conspiracy, firearms and fraud charges in connection with a plot to kill Shamsuddin Fassi or members of his family. Federal prosecutors had initially identified the target of the plot as Fassi's son Mohammed, known internationally for his lavish spending and frequently unpaid bills.

The Fassi family was living in Britain a year ago when Martindale, 41, was arrested for transporting an Uzi semiautomatic rifle and a .38-caliber revolver from National Airport into London's Gatwick Airport.

After the arrest, investigators in Scotland Yard's Anti-Terrorist Branch disclosed evidence suggesting that Martindale hatched the plot in his Fairfax home and the Washington office of his American Trade Group Inc.

A letter and statement written by Fassi's attorney, F. Lee Bailey, and released this week provided the Saudi sheik's first public reaction to the case since the conspiracy began unfolding.

The letter, dated Oct. 17 and addressed to Secretary of State George Shultz, and the statement ask U.S., Saudi and British officials to continue investigating various aspects of the case: specifically, allegations that a high Saudi official financed the plot and that the U.S. State Department intervened on Martindale's behalf when he was first arrested in London.

According to the statement, Fassi does not know why his murder was plotted but believes it has something to do with his relationship to the Saudi royal family.

"Someone may have been trying to adversely influence Fassi's son-in-law, Prince Turki Ben Abdulaziz, brother to Kind Fahd of Saudi Arabia," according to the statement.

Ibrahim Rawaf, Martindale's business partner in the American Trade Group Inc., was indicted as a coconspirator but remains a fugitive in Lebanon, a situation the letter said still poses a threat to Fassi.

Prosecution testimony during last week's five-day trial in U.S. District Court in Alexandria composed a tale of international espionage and intrigue that raised as many questions as it answered. A government witness, who received immunity for his testimony, claimed that the plot may have been financed by a Saudi minister of the interior.

Officials in the Saudi embassy in Washington would not respond yesterday to inquiries about the case.

Through Bailey, who could not be reached for comment yesterday, Fassi is also seeking an investigation into whether the State Department was involved in the decision of British authorities not to file more serious charges against Martindale, a former official of the Agency for International Development.

Martindale pleaded guilty in London last year to possession of the firearms and was fined $1,200. No further charges were filed against him in Britain, but U.S. officials subsequently began their own investigation, which led to last week's convictions. Martindale, who has maintained his innocence, is scheduled to be sentenced Nov. 2.