'Criminal negligence' behind death of Total boss
Russian investigators have said "criminal negligence" caused the crash at a Moscow airport that resulted in the death of Total's chief executive.
Christophe de Margerie died along with three crew members when his corporate jet collided with a snow plough.
Federal investigators said that the driver of the snow plough was drunk.
Investigators also said that "negligent" managers at the airport had failed to co-ordinate the actions of their employees.
The Investigations Committee of Russia, a federal agency which answers to President Vladimir Putin, is investigating the crash.
"It is already obvious that the cause of the events was not at all a horrific tragic confluence of circumstances, which is how representatives of the airport are trying to present it, but criminal negligence by officials who could not ensure the coordinated actions of airport employees," said committee spokesman Vladimir Markin.
Several officials at the airport were likely to be suspended, according to Mr Markin.
Russia's transport regulator is also investigating the crash, which it said happened in "bad visibility".
Mr de Margerie's jet had been due to fly to Paris from Moscow's Vnukovo International Airport.
Vnukovo is located south-west of Moscow and is used by President Putin and other government officials.
Pictures from the scene show the driver of the snow plough looking shocked, but walking unaided and without any obvious serious injury.
Mr de Margerie, 63, had been chief executive of Europe's third largest oil company since 2007. He was highly regarded within the oil industry.
According to Russia's Vedomosti newspaper, Mr de Margerie had met Russian Prime Minister Dmitry Medvedev at his country residence outside Moscow to discuss foreign investment in Russia.
Total is one of the biggest foreign investors in Russia and is planning to double its output from the country by 2020.
Analysis: Andrew Walker, Economics correspondent, BBC World Service
Christophe de Margerie leaves a large gap to be filled. He was a hugely influential figure in the global energy industry and a colourful and instantly recognisable character.
For colleagues as well as family, there's no question that it's a huge loss. But already the markets appear to think the company will cope. The board is seen as strong and a wobble in the share price seems to have been no more than that.
It is significant that Mr de Margerie was in Moscow. He took the view that the energy industry needed to go to difficult places. Russia is a prime example. A Total project there - a joint venture with Russia's Lukoil to explore for shale oil - has come to a halt due to Western sanctions.