The European Parliament on Thursday voted to set up a committee to investigate Volkswagen's emissions scandal and the probe could last up to a year, according to media reports. The German automaker had admitted in September that it rigged emissions tests by equipping diesel vehicles with a cheating software.

The EU inquiry will reportedly look into whether the regulatory authority that monitors the car industry was too negligent as it allegedly ignored suspicious pollution testing of diesel cars. The inquiry will also focus on alleged contraventions of EU law and "maladministration" in the application of the law, Sky News reported.

"For me, the diesel issue mainly has two dimensions,” Claude Turmes, Green Member of the European Parliament, reportedly said. "Firstly, it's about private companies organizing the largest industrial fraud ever."

"And, secondly, it's about public authorities in member states and on the EU level not intervening despite having relevant information," Turmes added.

Volkswagen said that 11 million vehicles -- mostly in Europe -- have been equipped with the so-called defeat devices that showed the vehicles' emissions far lower than they actually were.

"This inquiry must focus on the roles played by the responsible national authorities and the European Commission in allowing this regulatory breakdown to occur," Green deputy Bas Eickhout reportedly said.

On Thursday, Volkswagen announced that engineer Ulrich Eichhorn would return to the company to take on the role of research and development chief under a reshuffle of senior managers, according to Reuters.

In early December, Volkswagen said that the group's former head of research and development, Ulrich Hackenberg, left his position more than two months after he was suspended after the emissions scandal came to light.