ZURICH U.S. authorities have sought legal assistance from Switzerland's Federal Office of Justice in an investigation into tax evasion through offshore bank accounts at UBS UBSN.VX, Swiss media reported on Sunday.
Swiss newspaper SonntagsZeitung reported that Swiss authorities were looking into the request for possible legal and administrative assistance.
Swiss law does not allow banks to give out information on their clients except in cases of tax fraud.
Former UBS private banker Bradley Birkenfeld is facing prosecution for participating in a U.S. tax-evasion scheme.
Birkenfeld is scheduled to appear before a court in Fourt Lauderdale, Florida on Thursday, the paper reported.
Federal investigators in the United States believe some clients may have used offshore accounts to hide as much as $20 billion in assets from the Internal Revenue Service, enabling them to evade at least $300 million in federal income taxes.
UBS declined to comment.
(Reporting by Katie Reid, editing by Elizabeth Fullerton)