The leak on the Total gas platform was discovered last week

A gas leak on an offshore platform in the North Sea is costing its operators almost a million pounds a day in lost production.

Oil and gas company Total said it is "losing" an estimated £940,000 a day because of the leak on the Elgin PUQ platform, about 150 miles off the coast of Aberdeen.

The figure was confirmed following a Total press conference on Monday.

About 200,000 cubic metres of gas are escaping from the platform each day, coming out from a rock formation below the sea. It is then escaping into the air from a leak on the platform at the top of the well, about 80 feet above sea level.

Experts could board the platform within a couple of days to assess how to stop the leak. Total said it is "actively preparing" operations to regain control of the well.

The leak forced the platform's evacuation, removing all 238 workers, when it was discovered on 25 March, the Press Association reported.

One option for dealing with the problem is pumping mud into the well, which would need people to re-board the platform.

Total said it is in talks with the Health and Safety Executive about how this can be done safely and that it hopes outside specialists from Wild Well Control could board the platform, accompanied by Total personnel, within a couple of days.

The other option is to drill a relief well and a back-up relief well but this could take months.

Total, which is headquartered in France, has already mobilised two rigs to drill the relief wells and said both will move to the site when they finish their current operations.

One of them, Sedco 714, is drilling the Fettercairn field 248.5 miles north of the Elgin platform, while the other, Rowan Gorilla V, is drilling the West Franklin field 3.7 miles from the gas leak site.

Total said it is also considering using other drilling rigs so it has the "widest possible range of options".

On Saturday the multinational said the flare which had been burning on the Elgin platform had extinguished itself. The company had insisted the flare posed minimal risk. It was burning about 492 feet above sea level.

Patrick de la Chevardiere, chief financial officer at Total, said the leak does not appear to have had much environmental impact.

Speaking at a press conference, he said: "There's no crude oil involved here and therefore the current impact on and risk for the environment are relatively low. In addition, the leak is at the well head of the platform, above and not under water."

He added: "We are monitoring the air quality around the platform and the gas is dissipating at a satisfactory rate."

Mr de la Chevardiere said Total is working closely with government and regulatory authorities to deal with the situation.

He said: "The group is committed to mobilising all technical, human and financial means to resolve these issues as quickly as possible."