Volkswagen's Porsche division has replaced a top vehicle development manager suspended since the start of the Volkswagen group's scandal over diesel cars rigged to cheat on emissions tests.

Porsche said in a news release that Wolfgang Hatz, 57, would be replaced by Michael Steiner, 51.

Hatz served both as Volkswagen's head of engine development as well as at Porsche head of development. He terminated his employment contract "on his own initiative" due to the ongoing investigation.

Porsche said Hatz had cooperated with the effort to uncover who was at fault for engine control software that deliberately disabled emissions controls.

The company said its investigation "has so far turned up no indications he shared responsibility."

There had even been news media speculation in January that Hatz might return to the company.