Adamov, who was in charge of the Russian Nuclear Energy Ministry in 1998-2001, was detained in Bern at the request of the U.S. Department of Justice.
U.S. authorities charge Adamov and his business partner, U.S. national Mark Kaushansky, with misappropriation of $9 million that the U.S. government had allocated for the Russian nuclear security program.
According to U.S. legislation, Adamov may face up to 60 years in prison and a $1.75 million fine.
The Federal Court ruled Friday to extend Adamov's detention. This means that the former Russian minister will remain in custody at least as long as the Lausanne court considers the Justice Department's appeal.
Russia also sent Switzerland a request for Adamov's extradition on May 17 in the form of an arrest warrant, issued by the Moscow Basmanny Court. The Russian Prosecutor's office has opened a case against Adamov on charges of fraud and abuse of power.
