The state's top archaeologist believes two human bones found on the North Shore in recent weeks are from the same area and are "very likely" Native Hawaiian, but that neither their age nor ethnicity can be pinpointed.

Meanwhile, state transportation officials are conducting an internal investigation into who gave the OK for sand to be removed from the site where one of the bones was found.

A portion of a left femur was found by a groundskeeper on the grounds of Dillingham Airfield in Mokule'ia. The other bone, part of a jawbone, was found in sand taken to the property of a Waialua homeowner and is also believed to be from the airfield.

David Brown II, archaeologist for the state Historic Preservation Division, said the condition of both objects makes it difficult to determine age or ethnicity.

Brown said the femur was "broken about midway up the shaft." The bone was found "at surface" on Oct. 20 and appears to have been exposed to the elements for some time since it looks to have been sun-bleached.

"It makes it very difficult to make a determination (regarding age or other information) with all of that accelerated environmental and mechanical decay," he said.

Because the femur was found "at surface" and not in the presence of other bones, Brown said, it was likely moved there from its original burial place.

It would take "intrusive testing" to make further determinations but laws pertaining to the discovery of human remains bar the state from conducting such tests, he said.

There is "indirect evidence" that leads him to believe the bone may have belonged to a Native Hawaiian. Specifically, there are "a heiau and some platform structures and stone walls ... basically to the southwest, east, and southeast of where the find is," Brown said. "You have Hawaiian, pre-contact activity in and around that Dillingham Airfield and so it's very likely that the remains are Native Hawaiian, but that's kind of speculation based on the poor context of the find."

Brown said his office was informed by police last week that following recent heavy rains, a Waialua resident found a human jawbone fragment exposed in sand that had been dumped in his yard.

"It turns out (the resident) had received the sand from the contractor who was bringing sand in from Dillingham Airfield," Brown said. "So the Police Department was able to put two and two together and said these remains in the yard might have come from the sand that came from Dillingham."

As with the femur, Brown said, it was difficult to determine the age, sex or ethnicity of the jawbone because it had also appeared to have been exposed for a long time. Brown's office is working with Thomas Shirai, a lineal descendant in the general area, to examine burial sites around the area to determine where the bones should be reburied.

Scott Ishikawa, a spokesman for the Department of Transportation, said the sand appears to have been removed improperly by Stay and Sons Inc., a company contracted by the state to remove brush at the airfield at two separate times last year. The brush was placed on the ground in an unused portion of the airfield and sand was apparently removed from the site.

The state leases the airfield from the Army and "I believe there's some language that says you're not supposed to move the sand or any other type of material without any clearance," he said.

"We are interviewing the airfield staff right now on how the sand left the property and who gave the order to do so," Ishikawa said.

Officials with the Division of Conservation and Resources Enforcement are also looking into whether there were any violations of state burial laws.

Reach Gordon Y.K. Pang at gpang@honoluluadvertiser.com.