There is a strong allegation against Russia for having provided to Saddam Hussein with Intelligence on US military moes in the opening days of the US led invasion in 2003. A US Pentagon report said Russia passed details through its Baghdad ambassador.

The interesting part of the story is that one piece of intelligence passed on was false, and in fact helped a key US deception effort, the report said.  But Russia has denied it.

In retaliation, a Foreign Intelligence Service spokesman said that similar baseless allegataions concerning Russia's intelligence have even been made more than once,"

A US Pentagon report said Russia passed details through its Baghdad ambassador.
One piece of intelligence passed on was false, and in fact helped a key US deception effort, the report said.

The report also quoted an Iraqi memo, which mentioned Russian "sources" at the US military headquarters in Qatar.

"The information that the Russians have collected from their sources inside the American Central Command in Doha is that the United States is convinced that occupying Iraqi cities are impossible," said the Iraqi document, quoted by the Pentagon report as per BBC.