Members of the International Group for Historic Aircraft Recovery shot the images during a July 2012 trip to the island of Nikumaroro, Phlly.com reported Friday.
Inspired by an old photo of what could have been landing gear sticking out of the water off the island, the group spent 10 days and $2 million exploring the island and taking sonar images and underwater videos.
In March, a man conducting an online review of a sonar map from the expedition spotted a long, thin streak with a sonar shadow, indicating it had bulk. It's about the size of the Lockheed Electra Earhart was flying when she disappeared in 1937 during an attempted flight around the world.
The location of the streak is consistent with other evidence. It lines up with a debris field seen on video and the supposed landing gear from the old photo.
TIGHAR Executive Director Ric Gillespie is working to raise funds for an expedition to the island in 2014. Next time, however, he wants to take two ships -- one for underwater exploration and another for a better look at the island itself.