Aviation pioneer Amelia Earhart and her navigator vanished more than 75 years ago, but a new sonar image is giving American researchers hope that the mystery could soon be solved.

On Tuesday, the International Group for Historic Aircraft Recovery (TIGHAR), a U.S.-based organization that focuses on aviation archeology, posted a sonar image of what they believe may be an underwater wreckage of Earhart's ill-fated Lockheed Electra plane.

A sonar image that American researchers say may be the underwater wreckage of Amelia Earhart's Lockheed Electra. A sonar image that American researchers say may be the underwater wreckage of Amelia Earhart's Lockheed Electra. (Courtesy of TIGHAR)

Earhart and her navigator, Fred Noonan, were flying from New Guinea to Howland Island when they went missing on July 2, 1937, during Earhart's bid to become the first woman to circumnavigate the globe.

The researchers are operating on a theory that Earhart and Noonan managed to land on a reef near the Kiribati atoll of Nikumaroro and survived for a short time afterward.

The suspected wreckage sits about 180 metres below the surface of the water.

TIGHAR has launched a $3-million fundraising campaign to organize a new expedition to the remote atoll, where they hope to verify whether the image is indeed wreckage of Earhart's doomed plane.