Lawyers for a Georgian billionaire accused Credit Suisse Group AG of money laundering as they step up their fight with the Swiss bank over its handling of a former wealth manager who allegedly made unauthorized transactions to cover up trading losses.

Bidzina Ivanishvili’s lawyers filed the criminal complaint with Geneva prosecutors Tuesday, alleging that the bank failed to install adequate procedures to prevent money laundering, allowing employees to act with complete freedom. The complaint is based on hearings, a review of the evidence as well as information received from MROS, Switzerland’s Money-Laundering Reporting Office, the lawyers wrote.

“A limited examination of the dossier in this case revealed facts that lead us to conclude numerous acts of money laundering were committed within Credit Suisse,” to the detriment of Ivanishvili, according to the criminal complaint filed by his attorneys.

The complaint is at least the second to target Credit Suisse in a widening scandal that has put the spotlight on its wealth management unit and what it knew about allegations made by Ivanishvili and two other Russian clients about improper trading dating back to 2007. The Geneva banker -- who can’t be named under Swiss law -- has been charged with fraud and criminal mismanagement by Geneva prosecutors and is in detention in the Swiss canton as the Frenchman is considered a flight risk to France.

The Zurich-based bank said it is cooperating with prosecutors and put the blame on its former employee.

“The former relationship manager concealed his deceptions from colleagues and this is to the best of our knowledge an individual case,” the bank said.

A spokesman for the Geneva Prosecutor’s Office didn’t immediately return calls about the complaint. A lawyer for the former employee wasn’t available to comment.

The bank filed its own criminal complaint as an aggrieved party against its former employee on Dec. 23, two days after Ivanishvili lodged its first complaint against him on similar charges. Credit Suisse appealed a decision earlier this month to award Ivanishvili the status of an aggrieved party in the case, which forced his lawyers to return evidence they are sifting through until the appeal’s outcome is decided.