An Irma Stern painting was recently found covered in bills and letters, presumably used as a noticeboard, in a London flat.Stern is regarded as South Africa’s leading artist, whose works have recently been soaring in value. Although the painting was used as a notice board, it is not damaged – and it is still in its original form.

The ‘Arab in Black’ was painted on Stern’s first visit to Zanzibar in 1939, when it was still under the reign of an Omani Sultan – Seyyid Khalifa Bin Haroub. It had been in the same family since it was purchased directly from the artist by the present owner’s mother over 70 years ago, and had never before appeared on the market.

In the early 1960s, the painting the Arab in Black was put up for auction to raise money for the defence of Nelson Mandela and his co-defendants in their treason trial.

Mandela had been arrested in 1955 on a charge of high treason, which carried the death penalty, and the Treason Trial Defence Fund was set up to raise money for legal fees and to support the defendants’ families. The fact that it had such great provenance added to its value.

The painting was originally purchased by art collector, Betty Suzman, whose father, Max Sonnenberg MP, founded Woolworths. Betty was the sister-in-law of anti-apartheid activist Helen Suzman.

The painting was taken to Britain in the 1970s when the buyer immigrated to the United Kingdom and was subsequently bequeathed it to her heir, who loved the painting and they knew it had some value, but had no idea it was such an important work.

Hannah O’Leary, a specialist in South African art at Bonhams auction house, discovered the work by chance on a routine evaluation of client artworks.

The painting’s value was estimated to be R20 million and actually sold for R17.2 million – the second-highest price ever for a painting sold in South Africa. The highest price was reached last year when Strauss & Co sold Stern’s Two Arabs for R21 166 000.