The Swiss bank engaged in a “pattern of obstruction” by not sharing some information during past investigations into the lender’s ties to Nazis, the Senate Budget Committee said.

A cache of client files stamped “American blacklist,” a designation for those financing or trading with Nazis or Axis partners, was recently found by investigators probing Credit Suisse, one of Switzerland’s biggest banks and now part of UBS.

Swiss bank UBS is working with an independent ombudsman to shed light on Nazi-linked accounts, it said on Saturday, after the Wall Street Journal newspaper reported some accounts at collapsed bank Credit Suisse,

An investigation by a US Senate panel has found that troubled investment bank Credit Suisse concealed information during previous inquiries into Nazi-controlled bank accounts during World War II.

Investigators looking into Credit Suisse’s connections to Nazi-era account holders uncovered new evidence that the bank failed to disclose during earlier probes, US Senate Budget Committee leaders said Saturday.

Fresh look at archives unearthed Nazi-linked accounts discovered by bank in 1990s but never disclosed to investigators.