Total says wind is blowing gas away from flare on Elgin platform – but there is a high risk of explosion if two come into contact

A flare is still burning on the North Sea platform that has been leaking gas for the last four days.

Total, the French oil company that operates the platform, first disclosed that the flare was still burning late on Tuesday night. The wind is blowing the gas in the opposite direction but, if it should come into contact with the flare, there is a high risk of explosion.

David Hainsworth, health and safety manager for Total UK, told the Guardian that Total had not informed the media earlier the flare was still burning because "we have been trying to feed information that is pertinent as the situation was unfolding, the fact that the flare was burning was not one of the most pertinent parts of information. It [the flare] is not our immediate concern."

The fact that the flare is still alight was only made clear last night following a direct question on Channel 4 News. "I was asked a direct question by Channel 4. I can only answer questions," Hainsworth said. "[It was] not our number one top priority whether the flare was alight. We've been trying to get useful information to the media to tell [the public]."

He said the odds of the gas connecting with the flare and exploding were "low". "The wind is taking the plume of gas directly away from the flare. We do not believe the concentration of gas in the plume [at a] distance from the flare is flammable even if the wind direction changes." Total said weather forecasts predict the wind will continue to take the gas away from the flare.

"The flare may burn itself out. Because it's alight now doesn't mean it will be alight in a hour," Hainsworth added.

The RMT union said it was "beyond comprehension" that the flare was still burning.

All 238 staff were removed from Total's Elgin platform after the gas leak was discovered on Sunday afternoon, and Shell has moved 120 non-essential staff from its nearby Shearwater platform and Noble Hans Deul drilling rig. A shipping exclusion zone is in place two miles around the platform and three miles for aircraft.

Total said two firefighting ships are on standby near the platform, about 150 miles east of Aberdeen, and others may be mobilised soon. Hainsworth said the company was "evaluating options" on how to put out the flare and how to stem the leak.

He said international well control experts have flown to Scotland to advise the company on the best course of action. Options include drilling a relief well and sending experts on to the Elgin to kill the leak from the platform. The company said it may take up to six months to drill an emergency relief well.

Total is still investigating what caused the leak at the platform, which stands in 305 feet of water and links several wells to a nearby production platform, from where gas and liquids are piped to the mainland.

Shares in the French oil company fell 6% in Paris on Monday, wiping more than €5.5bn (£4.6bn) off its value, as analysts said a worst-case scenario could see costs for Total running to billions of dollars.

The Elgin platform produces about 3% of Britain's total gas output, according to Reuters. The area around Elgin is known as a difficult place to drill because of the unusually high pressure in the undersea gas reservoir that it taps.

Last year documents obtained by the Guardian showed the two rigs with the most frequent oil spills in the North Sea in recent years were owned by Shell and Total.

The papers, released under freedom of information laws, revealed for the first time the names of companies that caused more than 100 potentially lethal and largely unpublicised oil and gas spills in the North Sea in 2009 and 2010.

Total said it was liaising closely with the Health and Safety Executive, the Department of Energy and Climate Change, Marine Scotland and the coastguard. It added that the positioning of the flare and the platform had been specifically designed so that the prevailing winds would take any leaked gas away from the flare.