Recuers were put on full alert yesterday after a sick whale wandered into a large sea loch in the Outer Hebrides yesterday.

Workers at a local fish farm on the west side of Lewis raised the alarm at about 8.40am after seeing the 30ft-40ft creature beached in Loch Roag, near to the Old Pier at Breasclete, on the west side of Lewis.

Volunteers from the British Divers Marine Life Rescue attended the scene with specialist equipment and identified the seven-tonne creature as an adult northern bottle-nosed whale, which is an endangered species. Coastguards and police joined in monitoring the whale and a number of fishing and fish farm boats which work on the loch kept clear.

The whale was beached for a short time but managed to refloat itself and swam around the loch. However, a local vet was called out as blood was seen around its dorsal fin and in the water as efforts to assist it got under way.

The whale moved into the deeper middle channel of the loch by midday and there were hopes that it may swim out to the open sea. It was later seen heading in the direction of open water but last night it was not clear if it had managed to escape back to the ocean. Local vet Hector Low said: "We have a very ill animal that has become injured after wandering into shallow water. Hopefully it will be able to swim away. If not we may have to euthanise it."

Northern Constabulary warned the public to stay away from the area until further notice because of the risk of contamination from the whale's injuries.

Normally the species is found in deep waters in the North Atlantic where they travel in groups of up to 10.

Last year a female bottle-nosed whale died after becoming stranded in the River Thames.