AN OIL rig which grounded on a west Lewis beach two weeks ago has been towed back to sea tonight.

Two tugs were used to refloat the 17,000-tonne structure, Transocean Winner, shortly after 10pm to coincide with high tide.

The tug operation, using Union Bear and Union Princess, will drag the rig around 51 miles to the east side of the island.

It could take until as late as 7pm tomorrow to complete the operation.

Once in Broad Bay, underwater inspections of the rig will be made to check for damage.

Transocean Winner could remain in the bay until mid-September to allow for repairs and a decision on its final destination.

The rig was being towed from Norway to Malta, from where it was to be moved to a yard in Turkey to be scrapped, when it broke free from a tug in a storm and was blown on to the shore at Dalmore, near Carloway, on Monday August 8.

The rig grounded with 280 tonnes of diesel on board and two of its four fuel tanks were damaged in the incident, resulting in the loss of up to 53,000 litres of fuel.

The remaining 200 tonnes of hydrocarbons, mainly diesel oil with small amounts of base oil and brine, were transferred from the rig to the supply vessel Olympic Orion at the weekend.

A 300-metre exclusion zone was put in place while the rig was grounded.