(Bloomberg) -- Dieter Kiefer, the former head of UBS Group’s wealth management for Western Europe, is one of three former executives that French investigators are seeking to detain for questioning amid allegations the Swiss lender helped clients evade taxes, said a person familiar with the case.

French authorities in January issued arrest warrants for Kiefer, Philippe Wick, formerly in charge of French international clientele, and Olivier Baudry, who managed money placed in Switzerland by French clients, said the person, who asked not to be identified.

Arrests were requested by French investigative judges, led by Guillaume Daieff, after the three ex-UBS executives failed to show up for questioning, Bloomberg News reported last month. The three bankers have not been charged with any crime, and the warrants do not indicate that any of the three is officially a suspect in the criminal case, said the person.

The French charged the world’s largest manager of money for the rich last year with laundering the proceeds of tax fraud and ordered the Zurich-based bank to pay a security deposit of 1.1 billion euros ($1.2 billion) to cover potential penalties should it be sent to trial and found guilty.

Kiefer, Baudry and Wick didn’t return multiple calls and messages left at addresses in Switzerland.

Tim Cobb, a Zurich-based spokesman for UBS, declined to comment.

On the French case, the bank said earlier this week, “the matter remains in a formal investigation phase, there is nothing more to add at this point.” Previously, the bank said the French probe has become a “highly politicized process” and that it’s “taken significant and broad steps to ensure tax compliance of our clients and will continue to do so.”

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