The plot is thickening for the London-based Hong Kong Shanghai Banking Corporation, better known as HSBC.
Earlier this month, an international team of investigative journalists revealed documents they said showed that HSBC's private Swiss bank was involved in money laundering and helping some of its wealthy clients hide hundreds of millions of dollars from global tax authorities.
On Wednesday, officials with the Geneva public prosecutor searched the HSBC offices there, reportedly looking for "everything and anything we can find -- documents and files."
The prosecutor's office says its investigation is focusing on individuals. Reuters quotes Geneva Attorney General Olivier Jornot as saying officials are working to secure "all the information concerning the accounts and clients who have been mentioned as detaining funds resulting from criminal offenses."
The wire service notes this latest set of allegations against the the world's second-largest bank has also attracted the attention of financial authorities in the United States, the U.K., France, Belgium, Austria and Argentina.
This past weekend, a top HBSC official issued a very public apology, in letter that was published as a full-page advertisement in several newspapers.
In that letter addressed to HSBC customers, shareholders and colleagues, Group Chief Executive Stuart Gulliver said he wanted to offer some reassurance and "state some of the facts behind the stories."
Gulliver said HSBC's current standards were not in place at the bank's Swiss operations in 2008, when a former employee at the private bank stole data. He added the Swiss division has been "completely overhauled," with nearly 70 percent of its private Swiss bank accounts removed and the rest subject to more centralized control.
"We have absolutely no appetite to do business with clients who are evading their taxes or who fail to meet our financial crime compliance standards," he concluded in the letter.
The scandal has also made an impact outside of banking, in the media world. Earlier this week, the chief political commentator for Britain's conservative-leaning Daily Telegraph resigned, in part for what he describes as the Telegraph's minimal coverage of the story swirling around HSBC, one of the newspaper's advertisers.