The US Department of Justice alleged that the UBS group executive board that ran the Swiss bank’s daily business operations contributed to a conspiracy to defraud the US of tax revenue, the publication said.

However, in a statement sent to WealthBriefing, UBS said, "Neither the US Department of Justice nor FINMA allege that the Chairman or CEO of UBS had any knowledge of illegal offshore structures that occurred in the bank's US cross-border business. After concluding its own investigations, FINMA came to the conclusion that senior management of UBS did not have such knowledge."

UBS continued: "The allegation that Peter Kurer and Marcel Rohner knew about the offshore structures which were used to commit tax fraud or the like is wrong. No new documents nor facts have been announced or have emerged since the completion of FINMA's investigations and the announcement of the agreements UBS entered into with US authorities on 18 February."

Investment News, in its report, said the allegation is contained in a single paragraph of an 11-page exhibit attached to the bank’s settlement of a US criminal investigation filed with the court last month.

The latest report comes after UBS agreed more than a week ago to pay $780 million to settle criminal charges that it helped wealthy US citizens evade taxes. The bank has already moved to stop offering offshore banking to US clients. However, UBS is resisting demands by the Internal Revenue Service, the US tax authority, for the names of an estimated 52,000 US clients. The issue has thrown a harsh spotlight on Swiss bank secrecy laws.

“Executives on UBS’s executive board knowingly” failed to tell the Internal Revenue Service in September 2002 of an internal audit showing deficiencies in UBS’s implementation of its tax oversight obligations, prosecutors alleged.

The bank was required under an agreement with the US to report and withhold taxes on US clients, according to the exhibit, a document that constitutes a written accusation of crimes signed by prosecutors.

The DoJ did not identify Mr Kurer, then a senior company lawyer, or the nine other members of the executive board by name. Its accusations were levelled at UBS and unnamed executives who “occupied positions at the highest levels of management” and were termed “unindicted co-conspirators.” It did not say if any unindicted co-conspirators were on the group executive board.

The executive board’s September 2002 members were identified in UBS’s Annual Review that year, a public document. The panel was appointed and overseen by the company’s board of directors.

UBS’s $780 million settlement, which headed off a likely indictment, limits the bank’s exposure to prosecution but not that of its employees.

“If I were advising the individuals who served on that committee, I’d tell them to be concerned that the US government might bring charges,” George Clarke, a Washington criminal tax lawyer who represents clients with offshore accounts, was quoted by Investment News as saying. “These allegations are serious for the people individually.”

Mr Kurer joined UBS in 2001 as group general counsel and was appointed to the banker-heavy group executive board in July 2002. He became chairman of the board of directors last April as part of a boardroom shakeup.