A boomerang acquired by Captain Cook on his first voyage to Australia in 1770 may fetch up to $120,000 at a London sale, Christie’s International said.

The boomerang is being sold with two wooden clubs also believed to have been acquired by the explorer, and which are estimated at $40,000 to $60,000, the auction house said. They are being sold September 25 by a descendant of John Leach Bennett, a beneficiary of the will of Captain Cook’s widow Elizabeth, Christie’s said.

“It’s all in the provenance with Captain Cook objects,” Christie’s specialist Nicholas Lambourn, who found the boomerang a year ago, said. All three pieces have been “given the nod” by Adrienne Kaeppler, the leading academic authority on Cook, Mr. Lambourn said.

Cook became the first European to reach and survey the eastern coast of Australia. Joseph Banks, a botanist on Cook’s ship, the Endeavour, described the resident Aboriginals as “a very pusillanimous people” who brandished a “wooden weapon made something like a short scymetar.” According to the Oxford English Dictionary, the word “boomerang” derived in the early 19th century from the native Australian words “bumarin” and “wo-mur-rang.”

Up until now, only six Aboriginal artifacts from Cook’s first voyage have been traced, all of which are in European collections, Mr. Lambourn said.

In September 2005, a cup made out of the metallic element antimony that belonged to Cook — and had passed into the same collection as the boomerang — sold at Christie’s for $400,000 with fees, five times the estimate.