By Julian Ryall
Four dogs trained to detect the scent of human bones have found a site on a remote Pacific atoll where Amelia Earhart and her navigator, Fred Noonan, may have died on their ill-fated attempt to circumnavigate the globe in 1937.
The four border collies were taken to Nikumaroro, part of the Republic of Kiribati, as part of the latest expedition to the atoll by The International Group for Historic Aircraft Recovery (Tighar) and the National Geographic Society.
Tighar believes Earhart managed to land on Nikumaroro, which was at the time an uninhabited British territory known as Gardner Island, but soon succumbed to hunger, thirst or illness.
The Delaware-based organisation has carried out numerous visits to the island and discovered compelling indications that Earhart's Lockheed Electra landed there after being unable to find Howland Island, its intended target.
That evidence included aluminium skin from an aircraft, plexiglass from a cockpit, a zip made in Pennsylvania in the mid-1930s, a broken pocket knife of the same brand that was listed in an inventory of Earhart's aircraft and the remains of a 1930s woman's compact.
The theory is supported by British colonial records in Fiji reporting the discovery of the partial skeleton of a castaway who died shortly before the island was settled in 1938.
The bones were found in the shade of a tree in a part of the island that fits the description of the encampment that Tighar has been excavating. The site is dotted with the remains of small fires on which meals of birds, fish, turtle and even rat were cooked.
In an attempt to find conclusive evidence, such as a bone or DNA, forensic dogs were brought to the island for the latest search. All four dogs independently sat at the bases of a tree at the castaways' site and locked eyes with their handler - the way they are taught to "alert" for the scent of human remains.
Scientists say the dogs are able to detect the odour of human bones long after the bones have decomposed. Subsequent excavation of the site did not recover human remains.
Instead, archaeologists have recovered soil samples from different depths and will submit the samples to a laboratory in Germany that specialises in extracting DNA.
Researchers told National Geographic magazine that DNA from Neanderthals has been extracted from soil in a cave in France, although "the odds of securing DNA from a tropical environment like Nikumaroro are very long".
The Tighar expedition has coincided with the airing of a documentary on the History Channel in the US that claims a photo discovered in US archives proves that Earhart and Noonan were captured by the Japanese and transported to Jaluit in the Marshall Islands. The theory adds that they were later executed.
Les Kinney, a long-time proponent of the theory that Earhart and Noonan were on a spying mission for the US government shortly before the outbreak of World War II, told the Associated Press the image shows Earhart sitting on a sea wall with her back to the camera, Noonan standing with a group of islanders and a Japanese survey ship identified as the Koshu towing a barge carrying the Electra.
Tighar researchers say they have been aware of the photo for several years but have discounted it for a number of reasons.
The person identified as Earhart in the grainy picture has hair much longer than when she took off on the final leg of her journey, they claim, and the image used to corroborate the suggestion that the man is Noonan has been horizontally reversed, meaning that his distinctive parting and hairline no longer match. Tighar also points out that the ship is too small to be the Koshu and that what Kinney claims is the aircraft on a barge "is just an indistinct blob".
It has also been pointed out that the photograph is marked as being taken in 1940, three years after Earhart's disappearance.
Profile: Amelia Earhart
Earhart was the first woman to fly solo across the Atlantic. But in 1937, when she tried to fly around the world, her plane disappeared in the Pacific Ocean, and she was never seen again.
Accompanied by Fred Noonan, her navigator, she had taken off from Lae, in New Guinea, and was searching for Howland Island in the Pacific.
In her last radio transmission, she said they could not find the island and were running low on fuel.
At the time it was believed that their plane, a Lockheed Electra L-10E, had crashed and they had died at sea.
The US Navy searched the area for weeks, but the plane was never found. Earhart was legally declared dead in 1939.
Earhart's disappearance continues to fascinate people and has prompted numerous conspiracy theories, including the claim that she survived and assumed a new identity.