Marine biologists are reporting an unusual cluster of dead leatherback turtles off the coast of Scotland.

Four have been found in the last fortnight, including the discovery last week of a six foot long, 770lb turtle near Dunbar, East Lothian.

The reptile, an endangered species native to the Caribbean, was caught up in creel ropes and will undergo examination to determine its cause of death.

Experts at the Scottish Marine Animal Strandings Scheme (SMASS) said it was the fourth case of the species to be found dead off the Scottish coast during October.

The find follows the recovery of another leatherback which was caught in fishing lines off Drumbeg, Sutherland two weeks ago. Other animals were found off the Isle of Coll and on the Isle of Skye, north of Elgol.

Matt Barnes, of the Marine Conservation Society, said: "We get a few strandings in Scotland every year, so it's not that unusual. But to have four occurrences in such a short space of time is rather unusual."

The leatherback is the largest of all living turtles and animal experts said the latest find indicated "certainly a unusual cluster of cases".

A spokesman for SMASS added: "We have now had four reports of leatherback turtle strandings this month so far.

The spokesman appealed for people to look out for further strandings along the coast.

He added: "Please keep a lookout for any other strandings. We need your eyes on the sand to help us establish what's going on here."