Russian engineers secretly aided Saddam Hussein's long-range ballistic missile programme, the New York Times reported on Friday citing American government officials.
US investigators said that Russian engineers worked on the Iraqi programme both in Moscow and in Baghdad, and that some were in the Iraqi capital as recently as 2001, the newspaper reported, citing sources familiar with the situation.
The engineers who provided technical help for prohibited weapons projects before the war worked for a private company rather than the Russian government, the Times reported.
Their work raised questions about whether Russian government officials knew of this involvement in forbidden missile programmes, according to a person familiar with the US intelligence reports, the paper said.
After the 1991 Gulf War, Iraq was barred from building missiles with a range of more than about 95 miles (150 km).
Moscow denied any knowledge of Russian support for the prohibited missile programme.
"The (United States) has not presented any evidence of Russian involvement," said Yevgeny Khorishko, a spokesman for the Russian Embassy, told the Times.