A photograph by John Deakin seemingly showing a disgruntled middle-aged woman in the 1930s is actually of artist Francis Bacon, dressed in drag, the Guardian reports. Paul Rousseau, the collection manager at the John Deakin Archive, tipped off by a commenter on an earlier Guardian story, used CIA-developed facial recognition software to match up the image of the anonymous woman with that of the famous painter.

Deakin documented the Soho bohemian set extensively and was commissioned to take a number of pictures that Bacon turned into paintings. The photograph in question was among those found under Deakin’s bed and belongs to a set of 15 dating from 1945, possibly taken for Lilliput magazine. In trying to unmask the mystery woman, Rousseau began researching Deakin’s friends from the period.

“I quickly landed on his closest friends Denis Wirth-Miller and Richard (Dickie) Chopping,” Rousseau told the Guardian. “Denis was a painter and Dickie was semi-famous for designing the original dustjackets for the James Bond books… Dickie was known to love dragging up; he was dame every year at the RCA when he became a lecturer there in 1962. And there are many references to Bacon’s interest in drag, his wearing of women’s knickers and stockings.”

A short video posted by Rousseau shows the startling similarities between Bacon’s face and that of the mystery woman in the Deakin photo. Having confirmed Bacon as the “unknown woman,” Rousseau set about solving a slightly seamier mystery.

“Deakin was known to fiddle about with photos using basic overpainting techniques,” Rousseau noted. “Or did Bacon learn to manipulate his ‘moobs’ like that from his years in Weimar Berlin?”