Researchers believe they may have moved one step closer to uncovering what happened to US aviator Amelia Earhart, who disappeared in 1937 attempting to become the first woman to fly around the world.

According to official accounts, Earhart died when her plane crashed into the Pacific Ocean after running out of fuel.

However The International Group for Historical Aircraft Recovery (TIGHAR) believes that Earhart may have had a stranger fate, living as a castaway on the island of Nikumaroro after crash landing there.

They claim that initial measurements of human bones found on the remote Pacific island back up their theory.

The bones were originally judged to have been male by a British doctor when they were recovered on the island of in 1940.

The remains were lost and the discovery forgotten until TIGHAR found files containing the original skeletal measurements in 1998. On re-examining the measurements using contemporary techniques, forensic anthropologists said that the information was "consistent with a female of Earhart's height and ethnic origin".

Amelia Earhart
Amelia Earhert went missing in 1937 after running out of fuel. Getty Images

In preparing an update on the bone evidence, Dr Richard Jantz of the University of Tennessee noticed that the upper arm bone discovered, or humerus, had a length to radius measurement larger than that of the average woman of Earhart's generation.

"In other words, if the castaway was a middle-aged, ethnically European woman, she had forearms considerably longer than average," according to the statement.

Forensic imagining specialist Jeff Glickman has now examined a photograph of Earhart in which her arms are exposed, and found that Earhart's humerus-to-radius ratio was 0.76, matching that of the bones found on the island.

According to the original analysis, the humerus bone discovered on the island was measured to be 32.4cm long. The radius bone was 24.5cm, giving the arm a ratio of 0.756.

"The match does not, of course, prove that the castaway was Amelia Earhart but it is a significant new data point that tips the scales further in that direction," said TIGHAR.

Andrew Nelson, an anthropologist at the University of Western Ontario, told the Huffington Post that more information was required before the significance of the discovery could be established.

"When calculating ratios, you're on safer grounds than if you're trying to estimate absolute [measurement]," he said of the bones' estimated humerus-to-radius ratio. "I would like to see what sorts of variability there is around there because there could be a lot of other people out there who have that same measurement."

TIGHAR argues that Earhart made more than 100 emergency radio transmissions calling for help between July 2 and July 6 of 1937, which rules out the possibility of her plane crashing. The plane's engines would not have been working if it crashed into the sea.

According to their theory, rescue planes failed to spot Earhart's crashed aircraft as it landed on a reef near the island and sank into the sea after landing. Earhart's co-pilot is believed to have been injured in the landing and died shortly after, with Earhart surviving on the island alone until her own death.