Three executives dubbed "Germany's stupidest bankers" in the press have been suspended from state bank KfW over erroneous transfers of more than 500 million euros (710 million dollars) to the bankrupt Lehman Brothers, the KfW said.

Two board members and a top risk control manager were suspended "pending final clarification of the incident" following a meeting of KfW's supervisory board meeting attended by top ministers including Finance Minister Peer Steinbrueck, the bank said in a statement late Thursday.

A law firm has also been hired to see if further "consequences" are appropriate and the bank, already under fire over its rescue of IKB -- Germany's biggest casualty of the subprime crisis -- will subject its business procedures, especially those of risk management, to an "in-depth audit."

The bank state-owned lender mistakenly transferred more than 350 million euros to Lehman Brothers on Monday after the US investment bank filed for bankruptcy protection, and according to the Bild daily the total exposure has since been established at 536 million euros.

"I have never experienced anything like it in my life," Bild quoted Steinbrueck as saying after the meeting.