U.S. authorities are investigating German auto supplier Robert Bosch GmbH [ROBG.UL] over its role in Volkswagen AG’s (VOWG_p.DE) massive scheme to cheat U.S. emission standards, according to people familiar with the matter. Federal prosecutors with the U.S. Department of Justice are examining whether Bosch, the world’s largest auto supplier, knew or participated in Volkswagen’s years-long efforts to circumvent U.S. diesel emissions tests, the people said.