CNN  — 

French Budget Minister Jerome Cahuzac has resigned as prosecutors said they had opened a preliminary investigation into allegations that he had an undeclared bank account in Switzerland, officials said Tuesday.

His resignation was announced in a statement from the presidential palace. French President Francois Hollande removed Cahuzac at his request and appointed Bernard Cazeneuve to serve in his place, it said.

The announcement came shortly after prosecutors said they had launched the preliminary investigation into tax evasion in January.