Last week WealthBriefing reported the arrest in the US of Bradley Birkenfeld, an ex-UBS banker. Mr Birkenfeld is accused of assisting US citizens in tax evasion. More details are now beginning to emerge in the local Swiss press.

The arraignment of some 15 pages alleges falsification of Swiss bank documents and the IRS form W8 as well as sales of non-authorised products to US citizens by persons not registered as financial advisors with the SFC.

Mr Birkenfeld is apparently free on a bail of $2 million in Florida and is alleged to have agreed to co-operate with the US authorities in naming individuals and detailing the methods used by clients of UBS to evade taxation.

This follows a reported dispute between Mr Birkenfeld and UBS that began when he refused to sign a document which stated that the risks of his voyages to the US to see his clients were to be assumed by himself and escalated into a dispute about severance pay.

UBS is unable to comment on active legal proceedings.