German stock market operator Deutsche Boerse said on Wednesday that its clearing and settlement unit Clearstream is the target of a money-laundering probe in the United States. "Clearstream Banking has been informed that the United States Attorney for the Southern District of New York has made Clearstream subject of criminal investigation in connection with alleged violations of US money laundering and Iran sanction laws," Deutsche Boerse said in a statement. Luxembourg-based Clearstream was cooperating with the investigation which was still at a "very early stage," the statement added. At the end of January, the US Treasury said that Clearstream would pay the US $152 million to settle accusations it illegally helped Iran's central bank access the US financial system. The Treasury said that in 2007 and 2008, Clearstream held an account in a bank in New York on behalf of the Central Bank of Iran that contained $2.8 billion worth of securities, violating US controls on financial dealings with Tehran.