NEW YORK -- A Japanese military history buff has apparently undermined a new theory that Amelia Earhart survived a crash-landing in the Pacific Ocean during her historic attempted round-the-world flight in 1937.

The history blogger has posted the same photograph that formed the backbone of a History channel documentary that aired on Sunday that argued that Earhart was alive in July 1937 -- but the book the photo was in was apparently published two years before the famed aviator disappeared. The History channel is looking into the matter but stands behind its documentary.

The undated black-and-white photo is of a group of people standing on a dock on Jaluit Atoll in the Marshall Islands. One of the people seems to be a slim woman with her back to the camera.

The documentary argued that it proved Earhart, along with her navigator Fred Noonan, landed in 1937 in the Japanese-held Marshall Islands, where they were picked up by the Japanese military and held prisoner.

The History channel said Tuesday its investigators are "exploring the latest developments about Amelia Earhart and we will be transparent in our findings."

"Ultimately, historical accuracy is most important to us and our viewers," it said in a statement.

In the documentary, the photo is subjected to facial-recognition and other forensic testing, such as torso measurements. Experts on the show claimed the subjects are likely Earhart and Noonan.

A retired federal agent said he discovered the image in 2012 in the National Archives in College Park, Maryland. The blogger said he found the same image digitized in Japan's National Diet Library but it has not been authenticated.

The disappearance of Earhart and Noonan on July 2, 1937, in the Western Pacific Ocean has been the subject of continuing searches, research and debate.

A longstanding theory is that the famed pilot ran out of gas and crashed into deep ocean waters northwest of Howland Island, a tiny speck in the South Pacific that she and Noonan missed.

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AP investigative researcher Randy Herschaft contributed to this report.