Frankfurt: Deutsche Bank AG employees, who are suspects in a nationwide probe over possible tax evasion linked to trading of emissions allowances, were warned beforehand about a raid in the case, a prosecutor said.

The information was leaked to them before prosecutors searched Deutsche Bank's Frankfurt headquarters on April 28, Guenter Wittig, spokesman for the city's General Prosecutor's Office said in an interview. His office opened a separate probe in May to investigate who may have leaked the information, he said.

German prosecutors and tax investigators on April 28 searched Deutsche Bank, HVB Group and RWE AG as part of raids on 230 offices and homes. The German investigation involves 180 million euros (Dh830 million) of possible tax evasion and is targeting 150 suspects at 50 companies. The UK Revenue and Customs office raided 81 premises in the UK and arrested 13 people in England and eight in Scotland on the same day.

Munich's Sueddeutsche Zeitung newspaper reported the leaks, citing transcripts of the suspects' phone conversations intercepted by police. The transcripts didn't indicate that the employees took any action to destroy or obscure evidence, according to Sueddeutsche.

Wittig declined to comment on the Sueddeutsche report.

Deutsche Bank believes the allegations against its employees in the case can be rebutted and is fully cooperating with investigators, spokesman Klaus Winker said in a statement.

Before trading carbon dioxide certificates with any company, the lender checked it, he said.