Moscow Russia responded with silence Thursday after Georgia revealed a foiled effort by a Russian man to sell weapons-grade uranium, an episode that appeared to cast doubt on the nation's ability to halt the black market trade in nuclear materials.
The origin of highly enriched uranium seized early last year in the former Soviet republic remains unclear, and some experts accused Georgia of trying to embarrass Russia at a time of strained relations between Moscow and Washington.
The Russian government said nothing publicly about the inquiry. An unidentified official at the nuclear agency Rosatom, quoted by the Interfax news agency, denied Georgian accusations that Russia was not cooperating with an investigation of the case.
U.S. and Georgian officials told The Associated Press that Georgian authorities, aided by the CIA, set up a sting operation that led to the arrest last year of a Russian citizen who tried to sell a small amount of uranium enriched to about 90 percent U-235, suitable for use in an atomic bomb.
Georgian officials said attempts to trace the source of the nuclear material, and to investigate the man's claim that he had access to larger quantities of highly enriched uranium, failed because Russia did not cooperate.
The Rosatom official was quoted as saying that Georgian authorities had given Russia too small a sample to determine its origin, and had refused to provide other information.
Georgian Interior Ministry official Shota Utiashvili identified the man as Oleg Khinsagov, a resident of Vladikavkaz in North Ossetia, a region of Russia that borders Georgia.
Utiashvili said Georgian authorities had thwarted an earlier smuggling attempt also involving a small amount of highly enriched uranium in 2003, but gave no further details.
Russia's Federal Security Service, Interior Ministry and Rosatom did not respond to requests for comment.