Swiss prosecutors say they've opened a money-laundering investigation against a local subsidiary of HSBC following a report that the bank turned a blind eye to illegal activities of arms dealers and traders in blood diamond traders while helping rich people evade taxes.

Geneva prosecutors said the premises of HSBC's Swiss private bank in the city were searched on Wednesday. They said in a statement that they opened an investigation into suspected aggravated money laundering against the subsidiary and against persons unknown.

Prosecutors said the investigation stemmed from "the recent published revelations" about the private bank.