LONDON — A Banksy painting honoring Britain's health workers in the pandemic has sold for a record 16.8 million pounds ($23.2 million), auction house Christie's said Tuesday. Proceeds from the sale will be used to fund health organizations and charities across the U.K., it said.

The work by the mystery street artist, titled "Game Changer," first appeared on a wall at Southampton General Hospital in southern England in May, during the first wave of the pandemic. The black-and-white picture depicts a young boy sitting on the floor playing with a nurse superhero toy, as Batman and Spiderman toy figures lie in a wastepaper basket next to him. 

At the time it went up, the hospital said Banksy left a note for workers there saying: "Thanks for all you're doing. I hope this brightens the place up a bit, even if it's only black and white."

Christie's said the sale price was a world auction record for Banksy. The auction house said it will donate a "significant portion" of the buyer's premium to health organizations.

A reproduction of the picture will stay at the hospital for patients, visitors and staff, Christie's added.

"Banksy is an extraordinary artist who is a constant barometer of nationwide sentiment," said Katharine Arnold, who heads the European post-war and contemporary art division at the auction house. "With the perfect image of a little boy playing with his superhero doll, a nurse sporting the international Red Cross, he perfectly captured the essence of this moment in time."

The sale came on the day Britain held a minute's silence to mark one year since Prime Minister Boris Johnson ordered the first national lockdown.