BERLIN (AP) — Volkswagen says German prosecutors have widened their investigation of the emissions scandal to include the chairman of the company's board of directors.

Hans Dieter Poetsch was VW's chief financial officer when the company's scandal over cars rigged to cheat on U.S. diesel emissions tests broke in September 2015.

Volkswagen said in a statement Sunday that prosecutors in the German city of Braunschweig are investigating two members of the board including Poetsch, but didn't name the second person.

Prosecutors were already investigating former Volkswagen CEO Martin Winterkorn and another unnamed executive over allegations they didn't inform investors soon enough.

VW said "based on careful examination by internal and external legal experts," the company reaffirms its belief that board members fulfilled their disclosure obligation under Germany's capital markets law.