A former UBS private banker charged with helping a US client evade millions of dollars in taxes is set to plead guilty at a court hearing next month.

Bradley Birkenfield, 43, formerly a director in UBS’ wealth management division has indicated that he intends to plead guilty to a single charge of conspiring to defraud the United States, according to court papers released last night.

Mr Birkenfield, who faces a maximum five year jail term, had previously pleaded not guilty to the charge that relates to allegations he helped billionaire US investor Igor Olenicoff hide around $200 million from US tax authorities.

Mr Birkenfield was indicted by the US Department of Justice as part of a wide- ranging probe into tax irregularities at UBS that has also seen his former boss Martin Liechti, a senior UBS banker, arrested by US authorities.

Mr Liechti, who led the UBS unit where Mr Birkenfield worked until 2006, was detained as a material witness and released without charge.

According to a report this week, UBS has warned around 50 of its private bankers from entering the US because they may be detained as part of the probe.

UBS declined to comment.

The Securities and Exchange Commission, the US financial regulator, is conducting a separate investigation into UBS’ work for US clients.

Mario Staggl, a Leichtenstein banker charged at the same time as Mr Birkenfield, has been named a fugitive by the US.

Olienicoff, a real estate tycoon whose wealth is estimated at $1.6 billion by Forbes magazine, pleaded guilty to tax charges last year agreeing to pay $52 million in back charges, penalties and interest.

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