Apr.29 (GMM) Max Mosley has engaged an expert investigative company in a bid to identify the source of the surveillance that led to the sex scandal that looks set to end his FIA presidency.

The embattled 68-year-old has pledged legal action against the News of the World for revealing his prison-themed romp with five prostitutes, but it is believed that the investigation into his private life was actually conducted at significant expense over a long period of time by a third party.

Rumours indicate that the source of the investigation may even originate from within the formula one paddock, the German magazine Auto Motor und Sport claims.

Mosley's retaliatory investigation, waged by a specialty agency, has been going on for two weeks already, the magazine added.

It emerged at the weekend that Mosley had commissioned the British private detective outfit Quest to conduct surveillance on the whistle-blowing prostitute.