A stone cutting tool that could be twice as old as the pyramids has been found by a four-year-old boy under his mother's chair at Broome's speedway.

Eli Howlett was presented with a certificate of appreciation by Broome's Yawuru Aboriginal Corporation. ( Facebook: Lee Howlett )

Broome's Yawuru Aboriginal Corporation country manager Johani Mamid is amazed at the find and grateful to the child's mother for handing in the stone tool.

"They were at the speedway on the weekend, and the mother Lee, was sitting on her chair, and her son Eli had found the stone underneath and then showed his mum," Mr Mahmid said.

"It's amazing when someone who wasn't even looking for it just finds it, [and] actually identifies it as something that might be important.

"It's priceless; it's good when someone finds something like that because it's basically a piece of our culture coming back to us."

Dr Peter Veth is a professor of archaeology and Kimberley rock art, from the University of Western Australia, who has worked in the region for over 30 years.

Although he has only seen photos of the artefact, he has no doubts that it is an ancient Aboriginal tool.

"Looking at that artefact and the wear on it, it's probably about 5,000 to 10,000 years old," Dr Veth said.

Possibly used to butcher large animals

Dr Veth said that although the rock looked like a stone spear or arrow head, his experience of the ancient cultures of the Kimberley suggests it is more likely to be a cutting tool held in the hand.

"Given where it is, in the south-west Kimberley, I'm pretty confident that it's been used as a cutting or woodworking tool," he said.

"My best guess, looking at that, is that it's been used to process something like a marine turtle or a large animal."

Dr Veth said the kind of rock was not naturally found in the Broome area and was evidence of the extensive trading that took place across Australia in ancient times.

"It's an opaline silica rock that doesn't occur around the Broome catchment, so it's definitely been traded in," Dr Veth said.

"[Artefacts like this] are the only material record of quite complex long distance relationships between Aboriginal people."

Artefact may have spirit connected to it

Mr Mamid said the tool also had an important place in contemporary Aboriginal culture.

"Sometimes an artefact like that might have a spirit or something connected to it," he said.

"That's why you might get sick, or someone's family might get sick or unwell in some way.

"We're quite strict on that amongst ourselves, and that's why I didn't want to touch it."

The artefact will now be carefully studied to find what other information it can provide about traditional Aboriginal culture.

Dr Veth said Eli was a role model for anyone who may find Aboriginal artefacts.

"It's really exciting that a four-year-old actually saw that, found that, and brought it to public attention," he said.

"It's not the oldest material in the Kimberley, but you can never assume that just because something's lying on a pathway or something like a speedway, that it's just going to be rubbish."