Deutsche Bank says its co-chief executive Juergen Fitschen and chief finance officer Stefan Krause are under investigation as part of a tax evasion probe linked to the bank's emissions trading business.

The bank said Wednesday the reason Fitschen and Krause are being investigate is because they signed the company's 2009 tax declaration. The bank says the declaration was later amended in a timely way, but that prosecutors do not agree.

The Frankfurt prosecutors' office says 25 employees of the bank are suspected of serious tax evasion, money laundering and attempted obstruction of justice.

Prosecutors said 500 police officers swooped Wednesday on Deutsche Bank AG offices and private properties in Frankfurt, Berlin and Duesseldorf.

Deutsche Bank says it is cooperating with the investigation.