A Russian judge has found former atomic energy minister Yevgeny Adamov guilty of abuse of office and embezzling millions of dollars.
Yevgeny Adamov has denied the charges against him
Mr Adamov was extradited from Switzerland in December 2005. The US accuses him of embezzling $9m (£4.6m) it donated to improve nuclear safety.
A Russian prosecutor asked the court to sentence Mr Adamov to nine years in jail. He denies any wrongdoing.
He served as minister in 1998-2001. The US had also requested his extradition.
"The court has established that defendant Adamov committed fraud by stealing... abusing his office, which entailed substantial damage to state interests," the Russian judge said on Tuesday.
A formal verdict is expected later on Tuesday.