A spear thought to have killed explorer Captain James Cook belongs in a museum devoted to walking sticks.

That is the considered opinion of Cliff Thornton, Britain's leading expert on the explorer and president of the Captain Cook Society.

The spear, which was made into a walking stick, was sold for £135,000 at Edinburgh auctioneers Lyon and Turnbull to an anonymous private bidder last Wednesday.

It had been handed down through the family of one of Cook's fellow naval officers and bears the inscription: "From Adml. CBH Ross to Admiral Sir David Milen, GCB. Made of the spear that killed Captain Cook."

But Mr Thornton said: "The best place for the 'Cook' spear is in a museum devoted to walking sticks."

He said he has studied the events surrounding the death of the Middlesbrough-born explorer at Kealekekua Bay, Hawaii, in 1779. Eyewitness accounts do not refer to a spear but mention instead clubs and a steel spike.

He said that after Cook's death there was little trading done with islanders and so little chance of acquiring the spear.

Mr Clifton added that there are dozens of museums around the world claiming to have the weapon that killed Cook, including the Cook Birthplace Museum in Marton, Middlesbrough.

"Some people clearly have more money than sense," he said.

Philip Gregory, a spokesman for Lyon and Turnbull, said the auctioneers made clear that there was no definitive proof that the spear was the murder weapon.

He said: "We've never said 'this is the spear which killed Cook', but we say that it might be. We've always had a sentence explaining the position in the catalogue and all our literature.

"The buyer herself was very aware of that, but there's a nice story around the piece and no one can really say whether it was the weapon that took Cook's life or not."