A UBS client has been sentenced in New Jersey to five years probation after a guilty plea to hiding more than $6 million, according to Associated Press.

German-born US national Juergen Homann is one of at least five US-based clients of UBS to plead guilty in a continuing federal investigation.

Last year, UBS agreed to pay $780 million to settle criminal charges that it helped wealthy US citizens evade tax, and in a separate, civil case, the Swiss and US governments have agreed that UBS should hand over 4,450 client account details to the US authorities.

A whistleblower on UBS, a former employee called Bradley Birkenfeld, was due to start a 40-month jail term this month, and he has protested his punishment, which raises questions on whether such people will come forward in future to assist authorities in disclosing financial wrongdoing.