Swiss prosecutors have 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 blood diamond traders while helping rich people evade taxes.

The Geneva premises of HSBC's Swiss private bank were searched today, officials said.

The entrance of the HSBC Bank at the quai Wilson in Geneva, Switzerland

The prosecutors said they had opened an investigation into suspected aggravated money laundering against the subsidiary and against persons unknown.

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

Prosecutors said the investigation into HSBC Private Bank (Suisse) SA could be extended to people suspected of committing or participating in money laundering.

Franco Morra, chief executive of HSBC's Swiss subsidiary, said last week that it had shut down the accounts of clients who "did not meet our high standards", and that the revelations about "historical business practices" were a reminder that the old business model of Swiss private banking was no longer acceptable.

Last week's report from the International Consortium of Investigative Journalists and several news organisations found that the bank hid millions as it helped wealthy people around the world dodge taxes.

It was based on leaked documents covering the period up to 2007 and relating to accounts held by more than 100,000 people and legal entities from 200 countries, including Malta.

A former HSBC employee, Herve Falciani, gave the data to French tax authorities in 2008. France shared it with other governments and launched investigations.

French newspaper Le Monde obtained a version of the data and shared the material with the ICJ, which analysed the material with other international media.

These data showed that former Enemalta chairman Tancred Tabone had set up a Jersey offshore trust into which he deposited $1 million. It has been reported that Mr Tabone planned to transfer more funds, with the bank noting “the potential is evaluated [at] over $10m”.

It also showed that Maltese account holders had $687.4 million stashed away in HSBC Switzerland - more than people from Cyprus or Libya, among others.

There were 71 Malta-based clients holding 139 bank accounts but the ICIJ has, so far, only named Mr Tabone.

Times of Malta does not have access to the list.