The Federal Bureau of Investigation denied a report on Monday that it had detained Roman Abramovich, the Russian metals tycoon who owns London's Chelsea soccer club.
"We didn't arrest him. It's just not true," an FBI spokeswoman said in response to an unsourced report by Russia's RBK financial news portal that Abramovich had been held in the United States.
Abramovich's Moscow spokesman, John Mann, said earlier that the report was false.
The RBK report followed media speculation over the unexplained death in Britain of exiled Russian tycoon Boris Berezovsky, who launched and lost a multi-billion-dollar court case last year against Abramovich, his former business partner.
Abramovich, 46, is a major shareholder in London-listed steel firm Evraz, whose shares fell by more than 6 percent before recovering to trade 3.4 percent down on the day.