An underground North Sea gas leak has been successfully contained, Total has said.

Workers aboard the Elgin B platform discovered an unexpected flow of gas while drilling 140 miles off Aberdeen last month.

The incident is believed to have occurred more than two miles below the seabed in the Central Graben area.

Elgin B operator Total has cemented the bottom of the well, preventing gas from escaping to the surface.

A Total spokesman said: "Operations have now been completed and the bottom part of the well has been successfully cemented.

"At all times the well was under control at the surface and there was no loss of containment.

"Precautionary measures that were put in place during the operations, such as restricting access to essential personnel only and also the reduction of production, have now been lifted."

WWF Scotland director Lang Banks said: "It's good to hear that the repairs to the well have been completed and that there was no escape of gas and no harm to personnel.

"However, in the interests of staff and the marine environment, it's vital the relevant authorities establish exactly what happened and what lessons can be learned for the future.

"When it comes to the oil and gas industry there can be no room for any complacency."

Total was fined a record £1.1m following a major gas leak from the Elgin field in 2012.