A dispute arose on Friday (13 November) over a report by a German business weekly which stated the European Commission has known about Volkswagen's emissions cheating since 2011.

The magazine also wrote that commission officials who were frustrated with inaction by the commission tipped off the American NGO International Council on Clean Transportation (ICCT) to dig into the matter, but the NGO in question has denied the suggestion of commission whistleblowers.

Student or retired? Then this plan is for you.

If the report by the respected WirtschaftsWoche is accurate, that may mean that industry commissioner Elzbieta Bienkowska has misinformed both the public and the European Parliament, when she said the commission had "no indication" car manufacturers were cheating on emissions tests.

The journalists wrote that they have seen documents which prove the commission was aware of the fraud as early as 2011. They said Bienkowska's predecessor, Antonio Tajani, had been told of the scam.

The fraud became public last September, after the ICCT notified US authorities that there was something fishy about the test results of Volkswagen.

The magazine has the chair of the California Air Resources Board on record saying it were commission officials triggering the probe.

“It was officials from the EU administration who pointed out the possible cheating on nitrogen oxide emissions to the American environment group ICCT," said Mary Nichols.

However, press agency AFP published a denial from the ICCT about the involvement of commission officials in uncovering the scandal.

"ICCT was never informed by anyone about a possible cheating on emission testing" a spokesperson for ICCT was quoted as saying.

Following WirtschaftsWoche's report, Green MEPs Yannick Jadot and Karima Delli issued a press statement.

“If this information is confirmed, it means that the former and current industry commissioners, Mr Tajani and Mrs Bienkowska respectively, have hidden the facts and knowingly lied to the European Parliament,” they wrote.

It is not the first report saying the commission may have known more than it says it did.

Last month, the FT wrote that in 2013, Tajani had a letter exchange with then environment commissioner Janez Potocnik about the “significant discrepancy between the certified emissions and those actually observed on the road”.

In the same month Bienkowska, wrote MEPs that the commission “had no indications of defeat devices being used by car manufacturers in Europe."

In an e-mailed response on Friday to this website, commission spokesperson Lucia Caudet repeated what Bienkowska had written to MEPs: "The commission was not aware of any actual instances of fraud."