×

$1.5M painting discovered in use as a notice board

A painting valued at as much as $1.5 million was discovered hanging in the unknowing owner's kitchen in use as a bulletin board, an auction house said Wednesday.

The piece, "Arab in Black" by leading South African artist Irma Stern, has been linked to Nelson Mandela, according to Bonhams auction house.

Hannah O'Leary, Bonhams' head of South African art, found the painting in London when she went to a client's apartment to appraise their art collection.

Read More 500K to save Neil Armstrong's spacesuit

"I was undertaking a routine valuation when I spotted this masterpiece hanging in the kitchen covered in letters, postcards and bills," O'Leary said in a statement. "It was a hugely exciting find even before I learned of its political significance."

Bonhams will auction the painting in London on Sept. 9. It's estimated to sell for between $1 million and $1.5 million.

Stern donated the painting to an auction to raise money for Mandela's legal defense. The buyer eventually moved to the U.K. and passed the painting onto the current owner.

Mandela, who was eventually found not guilty, had been arrested in 1955 on a charge of high treason which carried the death penalty. Bonhams has advertised the artwork as the painting that helped save Mandela's life.