Iraq has told the United Nations that a senior official in Baghdad's biological weapons program was arrested trying to flee the country, a U.N. official said Tuesday.

The New York Times, quoting Iraq's U.N. Ambassador Nizar Hamdoon, said Nassir al-Hindawi is in an Iraqi prison after he was found with documents relating to the country's biological weapons program and evidence that he was about to leave Iraq illegally.The newspaper quoted unidentified Western diplomats as saying Hindawi had a forged passport.

Ewen Buchanan, a spokesman for the U.N. Special Commission, said Iraq notified the United Nations a few weeks ago of its claim that Hindawi was arrested and turned over documents, "which were nothing we had not already seen."

Buchanan said U.N. inspectors spoke to Hindawi last year but had not asked to interview him before being notified of his arrest. Buchanan said Hindawi was involved in Iraq's anthrax program but apparently not in the production of germ-filled warheads.

The Times said Western officials want to interview Hindawi outside the presence of Iraqi secret police - who have been at the interviews so far - in order to determine the scope of Iraq's germ weapons program.

"He would have been a gold mine of information," said Jonathan B. Tucker, a former U.N. inspector and arms control official, now a germ weapons expert at the Monterey Institute of International Studies in California.

Last month, a threatened U.S. military strike against Iraq was averted when Iraqi President Saddam Hussein agreed to allow U.N. inspectors to check presidential palaces and other sites.

U.N. weapons inspections of Iraqi presidential compounds came a step closer to reality Tuesday when 18 diplomats appointed by the United Nations to accompany inspectors arrived in Baghdad.