Heinrich von Pierer, the former chairman of Siemens and one of Germany’s most prominent businessmen, is being investigated by prosecutors for an administrative offence in the bribery scandal that hit the German conglomerate but he has escaped criminal charges.

Prosecutors in Munich, who already have 270 suspects in the €1.3bn ($2bn) scandal, said they had found no evidence of criminal behaviour by Mr von Pierer, who was chief executive or chairman of Europe’s largest engineering group throughout the alleged bribery under investigation.