The city-owned Stedelijk Museum had held the painting since 1940.
The culprit sold fakes of works by Richard Hambleton and Barkley Hendricks.
Five phone bidders from New York, London and Asia competed for what is now the artist’s sixth most expensive work.
An NFT artwork shakes the auction landscape, outdoor art venues become all-important during a pandemic year and museums diversify.
The heirs of Andy Onassis will part ways with the work at a Phillips evening sale on June 23rd in New York.
Experts had assumed the message was graffiti or a jab at the famously anguished artist.
“Head of a Bearded Man” has spent decades in the basement of the Ashmolean Museum.
The 21,000-square-foot painting is expected to be auctioned off this December.
Opening on July 16, the show explores how different artworks digest the past.