Authorities in Switzerland have launched an investigation into HSBC over allegations it advised wealthy clients how to avoid paying tax at its Swiss bank.
Swiss police searched the premises of HSBC's Swiss private banking arm in Geneva on Wednesday as part of the probe.
Swiss public prosecutors in the country have said they are probing HSBC Private Bank on allegations of money laundering as well as investigating "unknown individuals".
The investigation could be extended to people "suspected of or having committed, or participated in acts of money laundering" prosecutors Olivier Jornot and Yves Beertossa said in a statement.
The search of the bank's offices in Geneva are "ongoing", they added.
HSBC declined to comment.
The bank, mired in scandal over leak of documents which allege it advised rich and powerful clients around the globe, is already being investigated by authorities in Belgium, France and the US.
Meanwhile, in the UK the financial regulator earlier this week said it is "working closely" with HSBC to look at its cultural practice.
Following the leak of information about alleged goings on at the private bank over a week ago, HSBC said it would cooperate with relevant authorities.