The remains of a bear believed to be up to 40,000 years old have been recovered from a cave in Scotland, scientists said Monday.

The animal's skeleton was brought to the surface after a 12-year operation to unblock the entrance to the stream cave in Sutherland, where it was found by divers in 1995.

Experts from the Grampian Speleological Group removed the skeleton at the end of June using cases to protect the bones as they were carried through narrow passageways to the surface.

Scottish Natural Heritage (SNH) said it was the first time that such a complete bear skeleton has been found in Scotland.

Lesley Cranna, SNH's North Highland area manager, said the discovery will help fill in gaps in history.

'The bones will shortly be analysed and this sort of information helps us to build up a picture of the environment at the end of the last Ice Age.

'It's exciting to think that today in the 21st century we can piece together tiny fragments of events which took place many thousands of years ago.'

It is believed that the bear was washed into the cave at the end of the last Ice Age, making it at least 11,000 years old.

Animal remains in nearby caves date to more than 40,000 years ago, so the bear bones could be of similar age.

Bears were hunted to extinction in Scotland about 1,000 years ago.

The cavers recovered everything visible of the bear, which was 70- 80 per cent of the remains, including the skull, backbone, ribs, and most of the animal's long bones.

Experts at National Museums Scotland will now 'stabilize' the bones and radiocarbon date them to establish when the bear died and if the skeleton is that of a brown bear or a polar bear.

Ivan Young, Grampian Speleological Group treasurer, said it was satisfying to finally recover the skeleton.

'Having looked forward to it for so long, it was quite rewarding to get the bones out and get them over to the people at the museum because I think they are quite excited about getting a complete skeleton.'

'When we went to the cave in 1995 we were not expecting anything.'We've been in lots of other caves where you may find the odd rabbit bone but to find such a large collection of bones close together was quite unique.'