Berlin, Oct 8 (IANS): Investigators raided headquarters of German automaker Volkswagen in Wolfsburg and offices in other places on Thursday, the German public prosecution office in Braunschweig said.

Investigators searched the offices for "documents and data carriers that can provide information on the exact procedure of those involved in the manipulation of the exhaust emissions of diesel vehicles," Xinhua quoted the prosecution office as saying in a statement.

The search was carried out by three prosecutors with the help of the Crime Investigation Office in Lower Saxony state where Volkswagen's headquarters are located, according to the statement.

The prosecution office launched a probe into Volkswagen's emission scandal in late September after receiving several criminal complaints from citizens.

Volkswagen installed software in its diesel vehicle engines which would cheat emission tests. The scandal involved 11 million diesel cars around the world and forced the company to review all its investment plans in order to prepare for penalties of up to $18 billion in the US and expected massive compensation claims from its customers.

German Economy Minister Sigmar Gabriel said earlier on Thursday that Volkswagen should clear up the responsible people for the scandal and warned that workers of the automaker could not pay the price for "criminal behaviour of the managers".