A US court yesterday handed down the first prison sentence to a former US client of UBS in a ruling that will unsettle the Swiss banking group's other US former offshore customers.

Robert Moran, a wealthy US yacht broker, was given a two-month sentence for tax fraud by a court in Fort Lauderdale, Florida. The sentence was relatively lenient to reflect the cooperation of UK-born Mr Moran with the US authorities but it marked the first custodial term in deepening investigations into US clients of the bank.