Updated

Germany's Foreign Ministry is urging Switzerland to cooperate with an investigation into a case of suspected espionage.

Switzerland's ambassador in Berlin was called in for talks with German diplomats Tuesday over the arrest of a Swiss national on spying charges.

The suspect, a 54-year-old identified only as Daniel M., was arrested Friday in the German financial center of Frankfurt.

The Welt newspaper reported Sunday that M. was sent to Germany by Switzerland's intelligence agency to identify German tax investigators involved in the purchase of confidential Swiss bank client data.

Foreign Ministry spokesman Martin Schaefer said Wednesday that it's in Germany and Switzerland's interest not to harm bilateral relations.

Schaefer told reporters that "this naturally presumes that Switzerland helps shed light on the allegations put forward."