WASHINGTON — Scientists hoping to study the ancient skeleton known as Kennewick Man are protesting a bill they say could block their efforts.

They say a two-word amendment to a bill on American Indians would allow federally recognized tribes to claim ancient remains even if they cannot prove a link to a current tribe.

Scientists fear the bill, if enacted, could end up overturning a federal appeals court ruling that allows them to study the 9,300-year-old bones.

The skeleton was discovered in 1996 along the Columbia River near Kennewick, Wash., and has been the focus of a bitter nine-year fight.

The scientists successfully opposed a similar bill in the last Congress sponsored by then-Sen. Ben Nighthorse Campbell, R-Colo., chairman of the Senate Indian Affairs Committee. Campbell retired in January, but the bill has been revived in this Congress by the panel's new chairman, Sen. John McCain, R-Ariz.

"What they are trying to do is to change the statute so that it comes up with the absurd result that tribes can now claim skeletons to which they have no cultural connection," said Alan Schneider, a Portland, Ore.-based attorney for the scientists.

It is far from certain what tribe, if any, Kennewick Man would be assigned to, Schneider said: "He may not even be Indian at all."

Four Northwest tribes — the Umatilla, Yakama, Nez Perce and Colville — had claimed they were entitled to the ancient bones under the Native American Graves Protection and Repatriation Act. The tribes wanted the bones reburied without any scientific studies.

Last year the 9th U.S. Circuit Court of Appeals ruled that no direct link exists between the tribes and the skeleton.

Scientists say McCain's bill, with a two-word change, could nullify that ruling.

The change would add the words "or was" to a definition. It would then say that in the context of ancient remains, the term "Native American" refers to a member of a tribe or culture that is or was indigenous to the United States.

The Senate Indian Affairs Committee approved the bill on a voice vote last month. Rob Roy Smith, an attorney for the Confederated Tribes of the Colville Indian Reservation in Washington state, and other supporters say the bill would apply to future archaeological finds, and would strengthen the case of tribes across the country that want to claim and bury ancient remains.

But Andrea Jones, a spokeswoman for McCain, said attorneys have told the committee the bill would not apply to Kennewick Man, because the 9th Circuit has already made a decision.

Spokesmen for Sens. Gordon Smith, R-Ore., and Maria Cantwell, D-Wash., also say the bill does not apply to Kennewick Man.

Angela Becker-Dippmann, a spokeswoman for Cantwell, said that even if the bill is signed into law, tribes "will still have to prove a cultural connection" to an archaeological find before being allowed to claim them.

On the Net:

Information on the bill, S. 536, is at http://thomas.loc.gov/