The carcass is believed to be a sei whale

The dead animal was found on Sunday by a local resident and is believed to be a sei whale, larger than the more commonly-found minke whale.

Samples will be taken to confirm its type and to establish a cause of death, said the RSPB wildlife charity.

It is the second whale to have been stranded recently off the west coast - a beaked whale was found washed ashore on Mull last week.

'Beautiful creature'

The RSPB and Argyll and Bute Council are now studying options for removing the carcass.

Sarah Money, RSPB Scotland's warden on Coll, said: "This is extremely saddening to see.

"It is such a beautiful creature and as far as we can tell, there is no reason for this whale to have washed ashore."

She went on: "We have alerted the experts who plan to positively identify it as soon as possible and try to determine why this has happened."

A cuvier's beaked whale was found last week

She said sei whales were generally found much further out to sea, in mainly temperate and polar areas of both the northern and southern hemispheres.

They feed on small fish and plankton and sometimes find themselves targeted by killer whales.

No official population estimate has been carried out recently but the RSPB said: "It's believed there are only a few thousand individuals left in the North Atlantic, with evidence of depletion in some of the former whaling grounds."

Cally Fleming of the Hebridean Whale and Dolphin Trust said: "During the summer, we received roughly 3,000 whale and dolphin sightings off the west coast of Scotland.

"Of these, only five or six where thought to be sei or the larger fin whale.

"What a tragedy it is that one has washed ashore and died here."