An ex-wealth manager is in custody in Switzerland as a criminal investigation unearthed evidence linking him to a $109 million-fraud.

Zurich prosecutors are investigating a Swiss private banker who allegedly stole millions from clients, and stowed it at Union Bancaire Privée, UBS, Credit Suisse, and Vontobel, «Inside Paradeplatz» (in German) reported on Thursday. The Swiss banking blog cited a statement from Zurich’s prosecutor.

The case is unusual in that the banker previously worked for UBP until 2007, when he left for an external asset manager. In 2015, he then struck out on his own, according to his LinkedIn profile. He began his wealth management career at UBS in 2001, specializing in Turkish clients.

The banker’s clients accuse him of stealing as much as 100 million Swiss francs ($109). The Geneva-based wealth manager said it is joining the investigation against the banker, after lodging its own complaint. A spokesman for Zurich's prosecutor confirmed the arrest and investigation, emphasizing that UBP itself isn't being probed.