Roger Keller, an ex-banker of defunct Swiss bank Wegelin & Co Privatbankiers, has returned to Switzerland, after the U.S. failed to have him extradited from Germany, Reuters reported Dec. 9, citing his lawyer, Thomas Green.

Keller was arrested in February 2015 in Germany at the request of the U.S. government over allegedly aiding tax evasion. He served seven months in jail before being officially released by a German court on Dec. 9, Reuters reported, citing Green, who added that Keller had already been allowed to go to Switzerland a "few days ago."