A new doc on 1950s sex kitten Bettie Page uncovered previously unpublished — and rare, fully nude — photos that were secretly squirreled away during a shoot raided by New York cops.

Amateur photographer Dick Heinlein was headed for the Korean War in 1952 when he joined a “camera club” to shoot nude women. “Before nude pictures could be [legally] published, there were these ‘camera clubs’ in dingy New York offices, where men could go to photograph girls,” explains Mark Mori, who gathered more than 20,000 pics of Page for documentary, “Bettie Page Reveals All.”

In some instances, 30 or 40 men would pay to take a field trip organized by the “club,” where Page and other models were paid about $25 for a nudie shoot.

Heinlein and a group that included famed shutterbug Weegee were at a Westchester location where they captured Page frolicking outdoors completely nude with another woman. (Famous fotog Gordon Parks and cinematographer James Wong Howe were also members of the “camera clubs,” Mori said.)

“Nudity back then was very unusual,” Heinlein recalls in the film, out Nov. 22. “Out of the woods, here comes this squad car! They had their guns drawn on a bunch of photographers [ordering us], ‘Take the film out of your cameras!’ ”

But quick-thinking, dirty-minded Heinlein tricked the cops, and the images were preserved.

“When I opened the camera, the counter clicked back to zero, [so] I showed it to one of the cops [as if it was a roll with no pictures],” he said.

The whole group was arrested for disorderly conduct and indecent exposure (a charge Page feistily fought and got reduced). But Heinlein kept his private photos and entered the Army.

Mori’s revealing film also features Page’s narration in audio tapes she made before her death in 2008, pictures of Page as a teen in a home-made bikini, and interviews with devotees including Dita Von Teese, Hugh Hefner, Todd Oldham and Naomi Campbell. Mori’s next turning his attention to a doc on James Brown, he said.