Sydney - A boomerang that international auction house Christie's says was a souvenir taken by Britain's Captain James Cook on his voyage to Australia in 1770 is almost certainly a fake, an expert said Tuesday.

Aborigines in Sydney have urged the Australian government to bid for the boomerang when it goes to auction in London later this month.

There have even been calls for Prime Minister Kevin Rudd to talk British Prime Minister Gordon Brown into buying the wooden hunting tool and presenting it to Australia as an act of atonement for colonization.

"There is not the slightest shred of evidence that this boomerang was anywhere around Cook, even within 50 years of his death," ethnographer and collector Arthur Palmer told The Sydney Morning Herald newspaper. "I would have 100 boomerangs of that type and age here in my collection."

Environment Minister Peter Garrett said last week the government was considering bidding for the boomerang that Christie's says was given to Cook by Aborigines along with two wooden clubs. Leading the campaign to bring the boomerang back to Australia is Scott Morrison, a member of parliament whose Sydney constituency takes in Botany Bay where Cook landed.

"Kevin Rudd should use his relationship with British Prime Minister Gordon Brown to convince the UK government to purchase the boomerang and donate it to Australia in a gesture of friendship and to mark our shared heritage," Morrison said. (dpa)