German prosecutors have raided offices belonging to Deutsche Bank as part of an investigation into a tax evasion scheme involving the trading of carbon permits.
The Frankfurt prosecutor's office said 25 employees of the bank were suspected of serious tax evasion, money laundering and obstruction of justice.
Arrest warrants have been issued for five of those employees.
Deutsche Bank said it was co-operating fully with the authorities.
"Public prosecutors searched Deutsche Bank offices today in connection with investigations that have been under way since the spring of 2010 against individuals suspected of tax evasion in the trading of CO2 emission certificates," Germany's biggest bank said in a statement.