A flare is still alight on an offshore platform which has been evacuated following a gas leak, it has emerged.
However Total, which operates the Elgin platform, said the wind is blowing the gas plume in the opposite direction to the flare.
All 238 workers were evacuated from the company's Elgin PUQ platform, about 150 miles (241km) off the coast of Aberdeen, following the discovery of the leak on Sunday.
It could take as long as six months to drill a relief well to stop the release of gas.
An exclusion zone of two nautical miles (2.3 miles) has been set up around Elgin, with ships and aircraft ordered to stay away from the area.
Last night it emerged that a flare is still burning on the installation.
David Hainsworth, health, safety and environment manager for Total, told BBC Newsnight Scotland: "The flare is still alight on the main production platform, however the wind is blowing the gas plume in the opposite direction away from this flare.
"We know the weather forecast is such that the wind direction remains the same for the following five to six days and we're evaluating options to extinguish this flare."
A coastguard spokesman said flares on offshore platforms are commonly used to burn excess hydrocarbon gases that the rig does not use or capture.
Total E&P UK, which operates the Elgin platform, said it was taking "all possible measures" to try to identify the source and cause of the leak and to bring it under control.
It is looking at various options on how to stem the release of gas.
Shell has reduced its workforce on two offshore installations close to the Total platform as a precaution.
Around 85 staff have been taken off the company's Shearwater platform and the nearby Noble Hans Deul drilling rig, leaving a workforce of 117 people.
Shell also said it has brought forward plans for maintenance at Shearwater and is shutting down production in a "controlled manner".
A sheen on the water is present near the platform, estimated to extend over 4.8 square kilometres (1.85 square miles) and measure between two and 20 tonnes in volume.
Total said its preliminary assessments indicate there has been no significant impact on the environment because of the leak.
Offshore union RMT welcomed the quick evacuation of the platform but warned there could still be serious consequences.
RMT offshore organiser Jake Molloy said: "Total acted very swiftly in getting everyone off but the potential still exists for catastrophic devastation.
"If the gas cloud somehow finds an ignition source we could be looking at complete destruction.
"This is an unprecedented situation and we really are in the realms of the unknown but the urgent need now is to find a way of stopping the flow of gas."
RSPB Scotland called for transparency from Total.
Director Stuart Housden said: "We hope that, second to minimising risks to people, environmental considerations will be foremost in the mind of Total when considering their response to this situation.
"We urgently need to know exactly what environmental impacts the leaking substances could have."
The Scottish Government said it is monitoring the developments.
Environment Secretary Richard Lochhead said: "As the situation currently stands, impact on the environment, which is the Scottish Government's area of responsibility, is minimal."
Total E&P UK said it has met with the Secretary of State's representative, the Health and Safety Executive, the Department of Energy and Climate change, Marine Scotland and the Coastguard.