Memories of a long-demolished weapons laboratory are being revived to great interest as a documentary about the secret facility lets former workers give a rare glimpse into Japan's covert actions during the war.

The history of the Noborito Laboratory, formally called the 9th Army Technical Research Laboratory, had been shrouded in mystery because records of the institution were largely destroyed at the end of World War II.

The workers at the lab stayed mum about their experiences long after the war, until some were persuaded to go on record for the film, "Army Noborito Laboratory." The film, which was aired in Tokyo in August, has proved unusually popular for movies of its kind and is scheduled for release in other parts of Japan.