Officers from the Federal Criminal Police (BKA) and the public prosecutor were sent to the offices looking for documents relating to the transfer, which made KfW a laughing stock when it sent the money on September 15 as part of a liquidity exchange operation agreed to before the US investment bank went under.

The state prosecutor says it wants to establish whether those in charge of the corporation had “abandoned their asset management responsibilities to a criminal degree,” daily Handelsblatt reported on Wednesday.

“The fraud allegation we are investigating has nothing to do with anyone enriching themselves personally, it relates to the main suspicion of them knowing about the liquidity problems of the bank but nonetheless transferring the money,” a prosecutor spokeswoman told The Local on Wednesday. “If you know that something is not right, but you do it anyway, that can be included in fraud.”

She said the investigators, two from the prosecutor’s office and two BKA officers, went into the offices at around 9:30 am, and were still there at 1:30 pm.

Arrests were not immediately expected, she confirmed, but added, “The suspects have already been informed, and will be questioned once we have analyzed the material seized. It concerns the six then members of the board, and the head of the risk management and risk controlling department. All are men.”

A spokesman for the KfW told the Handelsblatt newspaper, “The KfW will provide all requested information and documents to the state prosecutor for the investigation.”

KfW is now only likely to get just half of the money back via insolvency proceedings at Lehman.

Three bank officials called “Germany’s dumbest bankers” have since been suspended for the expensive cock-up.