Unlocked: remains that hold key to origins of first Americans

Nine years after the 9,300-year-old remains of so-called Kennewick Man were discovered partly buried near a stream, scientists have finally begun studying one of the oldest and most complete skeletons found in North America. Some experts believe it could yield important clues about the origin of the original pop-ulation of the Americas.

The remains had been locked away since their accidental discovery by students in Washington state in 1996 because of a legal dispute over who should have access. Native American tribes had said the bones should be reburied without scientific examination, claiming such scrutiny would be desecration.

In February 2004, a panel of judges ruled in favour of eight scientists who filed a lawsuit seeking the right to study the remains and said there was no link between the remains and five Native American tribes who opposed the research. Scientists have already taken scans of the pelvis and skull and a dozen experts have converged in Seattle to begin 10 days of further, more comprehensive study.

After that, the remains will be returned to the Army Corps of Engineers, which owns the land along the Columbia River in Washington where they were found. They will then be returned to the University of Washington's Burke Museum, where they have been held in a vault that requires two keys to open.

The aim of the scientists is to glean what details they can about the way Kennewick Man lived and died. "This is something that should have been done years ago," the archaeologist Jim Chatters, the first researcher to inspect the bones, told the Seattle Times. The work on Kennewick Man will further fuel the already often ferocious debate about the origins of the native populations of the American continent. Tom McClelland, a sculpture instructor, and Mr Chatters had reconstructed the features on the skull and studies concluded that the facial features of Kennewick Man did not match those of Native American tribes.

The most famous image of his face may also not be accurate. An early reconstruction depicted him as looking like the thin-faced actor Patrick Stewart. A later computer reconstruction suggested slightly different features, with a wider nose, fuller lips and deep-set eyes.

Many scientists believe the first New World inhabitants arrived in a wave about 11,500 years ago, walking across an Ice Age land bridge between Siberia and Alaska, but some believe some discovered skeletons and scattered evidence of earlier settlements may indicate several waves of migration from different parts of Asia and the Pacific. These people - many based at Texas A&M University - are usually known as the "Pre-Clovis" group, a reference to their belief that human populations predate the 12,000-year-old skeleton found at Clovis, New Mexico, in 1908.

Some scientists say Kennewick Man's skull most closely resembles the Ainu, an aboriginal group that still lives in northern Japan but does not resemble the modern inhabitants.

The Corps of Engineers has forbidden the researchers to glue the bones back together. The best evidence of lineage would come from DNA analysis. Scientists tested small leg-bone fragments several years ago with no success but the Corps has refused permission to take any more samples from the skeleton.