"After discovering the case, FINMA filed a criminal complaint with the Swiss Office of the Attorney General," FINMA said in a statement. "The two authorities are coordinating their procedures."

Kuka's website lists Ziegler as a board member. Earlier on Wednesday he resigned from the boards of two Swiss companies, steelmaker Schmolz & Bickenbach and industrial surfacing solutions provider OC Oerlikon.

Ziegler could not immediately be reached for comment.

(Reporting by John Miller; Editing by Michael Shields)