The plane crash which killed Christophe de Margerie, the CEO of French oil giant Total, was allegedly caused by a snow plough operated by a drunk driver, an initial probe suggests.
Investigators said the driver of the plough, with which the private jet carrying de Margerie collided in Moscow, was reportedly under the influence of alcohol.
"It has been determined that the driver of the snow plough was under the influence of alcohol," the chief of Russia's Investigative Committee Vladimir Marking told reporters.
Other possibilities are also being considered for the cause of the crash, which killed four people including the chief executive.
Markin added: "There is a possibility that a number of airport staff will be suspended from carrying out their duties pending criminal investigation."
The Falcon-50 plane crashed in the Vnukovo 3 Airport in the Russian capital on Monday evening, local time.