WASHINGTON (AP) — A man wanted by Liechtenstein for leaking secret banking information that identified millionaire tax cheats across Europe and the US has described to congressional investigators how money was concealed.

Lawmakers played a videotape of the testimony by Heinrich Kieber at a congressional hearing yesterday that revealed rare details of offshore practices at two European banks. At the hearing, Swiss banking giant, UBS AG, announced that because of recent revelations, it will stop offering US clients offshore services through branches based abroad.

Kieber appeared only as a silhouette against a white screen with eyeglasses and a balding head apparent. Kieber is living under a new name in an undisclosed witness protection programme, according to lawmakers. He has never spoken publicly about his role in exposing tax shelters he says were used by Liechtenstein's LGT group.

In the videotaped interview with the congressional investigators, he described ruses that he saw while working at the bank, which he said were used to cover the tracks of money moved into accounts.

The hearing by the Senate Homeland Security and Governmental Affairs investigations subcommittee highlighted offshore tax abuses that they believe cost the US government about $100 billion a year.

The hearing came a day after the panel released a 109-page report that took aim at LGT, owned by Liechtenstein's royal family, and UBS, one the world's largest wealth managers.

Mark Branson, chief financial officer of UBS' global wealth management, said at the hearing that the bank regrets "any compliance failures that may have occurred" and will now provide banking or security services to US citizens only through companies licensed in the United States. He said the bank also is working with US authorities to identify clients involved in US tax fraud.

LGT refused to send a representative but said in a statement that it had cooperated by sending a senior official for a lengthy interview and providing all the documents requested by the panel. Both LGT and UBS came under withering criticism from the lawmakers.

"Tax havens are engaged in economic warfare against the United States and honest, hardworking American taxpayers," said Democratic Sen. Carl Levin, chairman of the subcommittee. "Today we will look at two banks that relied on secrecy and deception to hide, not just the tax avoidance schemes of their clients but the actions they themselves took to facilitate US tax evasion."