Search teams fear a worker has plunged into the North Sea from an oil rig.

Coastguard teams have scaled back searches for the 49-year-old, who is believed to be from Aberdeen.

The alarm was raised at about 9.20pm on Tuesday after he could not be located on board the Noble Lloyd Noble installation. All operations on the rig have been stood down.

Police Scotland confirmed there does not appear to be any suspicious circumstances. The man's family have been informed.

Detective inspector Norman Stevenson said: "An extensive search has been carried out which has involved a search and rescue helicopter as well as standby vessels and a platform supply vessel.

"The next of kin of the man have been informed of the ongoing enquiries and further information will be made available to the public when we have it.

"There are no apparent suspicious circumstances."

A team of officers have flown to the installation to help with the investigation.

Statoil, which operates the installation, has mobilised emergency response teams in Aberdeen and Stavanger to help support staff.