US aircraft history buffs are hopeful that tiny bones along with artefacts from the 1930s found on a remote Pacific island may reveal the fate of pioneering aviator Amelia Earhart.

In one of aviation's most enduring mysteries, Earhart took off from Lae, in what is now Papua New Guinea, while attempting to circumnavigate the globe via the equator in 1937 and was never seen again.

A massive search at the time failed to find the flyer and her navigator Fred Noonan, who were assumed to have died after ditching their Lockheed Electra aircraft in the ocean, according to the Amelia Earhart Museum.

Now aviation enthusiasts from US-based group The International Group for Historic Aircraft Recovery (TIGHAR) say they have evidence suggesting the pair made it safely to Nikumaroro Island in Kiribati and lived as castaways.

TIGHAR executive director Rick Gillespie said the group, which has carried out 10 expeditions to Nikumaroro over the past 22 years, found three small bone fragments on the uninhabited island earlier this year.

Gillespie said the bones appeared to be part of a human finger, although they could also be from a turtle, and had been sent to the Molecular Science Laboratories at Oklahoma University for DNA analysis.

"We're very hopeful that this will produce the result we're looking for," he told the Australian Broadcasting Corporation Thursday.

Backing Gillespie's theory that Earhart ended her days stranded on Nikumaroro, he said TIGHAR also found artefacts dating from the 1930s, including a woman's make-up compact, broken mirror and small US-made bottles.

"We have every reason to believe that this is the site where Amelia Earhart lived and died as a castaway," he said.

Gillespie said his decades-long quest to determine Earhart's fate had involved "many ups and downs", so he was not yet claiming to have definitive proof she washed up on Nikumaroro but the possibility was worth investigating.

"The magic of the Earhart mystery is such that just having a bone, that may be a human bone, that may lead to DNA that may turn out to match Earhart's DNA is of great interest," he said.

He said even if the Oklahoma DNA tests showed a link to Earhart, the bones would be tested by a second independent laboratory to verify the findings.

"This has been a very rigorous investigation," he said.