A recently discovered photograph, found in the National Archives among previously top-secret documents, may be a major new piece in the 80-year-old mystery of what happened to pioneering airwoman Amelia Earhart. The story of the photograph will be told in a History Channel documentary that airs this Sunday, July 9 at 9 p.m. ET, and the outlines of the tale the photograph may suggest were part of a Today show piece this morning, and reported on by People Magazine.

Retired US Treasury Agent Les Kinney is an Earhart buff who first discovered the photo in 2012. The photograph, taken the year of Earhart's disappearance along with her navigator Fred Noonan, is labeled only with a location: Jaluit Atoll, a Pacific island near Earhart's destination that was under Japanese control at the time. Kinney says in the documentary that the photograph was misfiled, and he tells People, "That’s the only reason I was able to find it." This suggests that agents in the US government likely knew about Earhart's whereabouts, but kept them secret, and that she and Noonan essentially became prisoners of war in a war that the US had not even yet entered.

The photo shows what appear to be a Caucasian male, with similar hairline and features to Noonan, standing on a dock near a seated woman who can be seen only in profile, who appears to be Caucasian also and with short-cropped hair like Earhart's. In the background, being towed by a ship, is what looks like Earhart's plane.

The theory, according to documentarist and former executive assistant director of the FBI Shawn Henry, is that Earhart and Noonan were taken hostage by Japanese soldiers and held in a prison in Saipan — rumors of sightings of Earhart on the island of Saipan date back to a 1990 episode of Unsolved Mysteries in which an elderly Saipanese woman claimed to have witnessed the executions of Earhart and Noonan.

It seems that Earhart and Noonan may have been blown off-course and either crash-landed or made an emergency landing as they ran out of fuel. The ship that can be seen in the photograph is a Japanese military vessel called the Koshu Maru.

Photo recognition experts testify to the likenesses of Noonan and Earhart in the documentary, though it is an 80-year-old image in which the figures are fairly small and out of focus.

Earhart's two attempts at a round-the-world flight, including an earlier attempt in March 1937, originated out of Oakland, California. The second attempt, in which her plane went missing on July 2, 1937, began with an Oakland-Miami flight, and Earhart was nearly across the Pacific and back to the US when she and Noonan disappeared.

Amelia Earhart: The Lost Evidence airs Sunday on History, if you want to learn more about the unraveling mystery.