With major operations in Switzerland, London and Hong Kong, the private bank’s office employs several hundred staff.
Following searches in two HSBC offices, the Geneva prosecutor’s office said its latest investigation may also be extended to individuals who are accountable to a fine and up to five years in prison.
Attorney General Olivier Jornot told reporters: "As of now, we aim at securing all the information concerning the accounts and clients who have been mentioned as detaining funds resulting from criminal offences."
The authorities are said to be on look out for all documents as well as complete information, which will allow them to analyze the situation in a better manner.
HSBC Swiss private bank chief executive officer Franco Morra was quoted by BBC as saying that accounts were closed last week from clients who were not up to its standards.
Geneva prosecutor Yves Bertossa said in a statement: "A search is currently under way in the premises of the bank, led by attorney general Olivier Jornot and the prosecutor."
The raid follows recent allegations that emerged against HSBC that its Swiss banking arm helped wealthy customers avoid tax payments in addition to hiding their assets.
Image: 8 Canada Square, the world headquarters of HSBC in Canary Wharf, London. Photo: courtesy of Michael Pead