German carmaker Volkswagen on Wednesday rebuffed a media report claiming that at least 30 Volkswagen managers were aware of the company's emissions cheating scandal, according to dpa. "The number is divorced from any basis in fact," a company spokesman said in response to a report posted by German magazine Spiegel on its website. VW's revelation that it manipulated tests on about 11 million vehicles around the world has already sparked a major shakeout in the group's management, with several top executives having been sent on leave. The group's new chief executive, Matthias Mueller, is to join the head of the VW brand Herbert Diess on Thursday in Dresden to report to about 400 of VW's senior managers on the company's progress in clearing up the scandal. A third US federal agency will launch an investigation of the embattled car company, joining Environmental Protection Agency regulators and Justice Department prosecutors. The Federal Trade Commission (FTC) will investigate VW's advertising for its "clean diesel" vehicles, according to Bloomberg Business. The FTC can levy fines for misleading advertising.