An art expert has found a painting valued at up to $1.5 million being used as a noticeboard in a London flat without the homeowner being aware of the value of the piece.
The piece is called "Arab in Black" and was painted by one of the most famous South African artists, Irma Stern.
According to the Bonhams auction house, the piece was once sold to help fund Nelson Mandela’s legal defence.
Bonhams' head of South African art, Hannah O'Leary, found the painting in London during an evaluation visit to the flat.
O'Leary said "I was undertaking a routine valuation when I spotted this masterpiece hanging in the kitchen covered in letters, postcards and bills."
She added, "It was a hugely exciting find even before I learned of its political significance."
This isn’t the first time the painting has been put up for auction.
In the early 1960s, artist Stern sold the painting to an art collector at an auction to help fund Nelson Mandela’s legal defence. Back then, Mandela was on trial for treason, a crime that carried the death penalty.
Giles Peppiatt, director of Bonhams South African art department, said the painting was a very important piece that formed a significant part of Mandela's defence fund.
The buyer moved from South Africa to the UK after purchasing the painting and left it for the current owner.
Peppiatt said the owners of the painting were "shocked" to discover its history.
The painting is set to be auctioned in London on Sept. 9. It is expected to fetch between $1 million and $1.5 million.