KROLL, the world’s biggest corporate-investigations firm, is itself under investigation by authorities in Russia.

The Russian parliament, the Duma, and the country’s state prosecutor have each started a probe into the American firm, now owned by insurance giant Marsh McLennan, allegedly for not having a licence to conduct investigations in Russia.

Kroll said: “We are aware of the investigation,” but refused to make any further comment.

Sources say Kroll has caught the eye of some members of the Russian political elite as a result of its association with Mikhail Friedman, the oligarch behind Alfa Group, the banking and telecoms conglomerate.

Alfa Group has for nearly two years been embroiled in a complicated legal battle over the ownership of its holding in Megafon, a telecoms group. Friedman, who said Alfa owns its stake through a Bermuda company called Ipoc, was accused of acquiring the stake illegally. The case continues.

Kroll is thought to have attracted criticism after it was alleged that the firm had done some investigations of the telecoms minister on behalf of Friedman, who is worth an estimated £5.6 billion.

A former director of Kroll told The Sunday Times: “Most foreign corporate-investigation firms working in Moscow don’t have a licence because it’s just too hard to get one.”

In calling for an investigation into Kroll — which has had an office in Moscow for over a decade — Nikolai Leonov, a Duma member, reportedly said: “With big business entities such as Alfa Group hiring foreign detective agencies for ‘sensitive assignments’, a dangerous trend is emerging of Russian citizens being harassed.”