Transport Minister Alexander Dobrindt told reporters in Berlin on Thursday that government investigators sent to investigate at VW's headquarters had received the admission from company officials.

Dobrindt said that the number of cars affected “will be clarified in the coming days.”

“For this reason, we will also carry on working intensively to find out exactly, together with VW, in detail which vehicles are affected so that we can further inform the public.”

Dobrindt said that most of the vehicles involved in the manipulation had 1.6- or 2-litre diesel engines.

VW is “working on” a list of the affected models, but “can't yet say when it will be published,” a VW spokesperson told Bild.

The EA 189 motors involved in the emissions scandal are also found in Audi's A1, A3, A4 and A6 cars, an Audi spokesperson tol the tabloid.

The Transport Minister did not say whether the vehicles affected would have to be removed from circulation.

But he added that cars from other manufacturers would now be tested to see if the problem is more widespread.

SEE ALSO: BMW diesels '11 times over EU pollution limits'

VW had already admitted that on-board computers in around 11 million cars worldwide included a program designed to reduce cars' emissions levels if it detected they were being tested.

The cars reduced their emissions of nitrogen oxides dramatically under testing conditions.

The scandal led to VW CEO Martin Winterkorn's stepping down on Wednesday evening.