Fiona Bruce and Philip Mould with the early Freud work Image: BBC Fiona Bruce and Philip Mould with the work attributed to Freud
Image: BBC

The portrait, which has been valued at £300 000, was acquired by one of Freud's rivals, artist Denis Wirth-Miller. The work was given to Jon Turner by Miller. Turner has spent years trying to authenticate the painting.

Miller gave Turner the portrait, reportedly saying: ''I want you to sell this picture as publicly as possible. I want you to humiliate Lucian Freud.''

Image: BBC Image: BBC

Freud and Miller studied together at the East Anglian School of Painting and Drawing, where Miller acquired the painting, which is believed to have been painted in 1939.

Notoriously difficult in character, Freud frequently denied painting the portrait. In 1985, Christie's identified the piece as a work by Freud, only for the artist to claim it was not his.

As part of their investigation, Fiona Bruce and art historian Philip Mould spoke with Freud's solicitor, who had notes on a telephone conversation with Freud about the painting, which took place in 2006.

Freud stated in the conversation that, although he had started the painting, another artist had finished it and therefore he would not claim it as his own.

Experts analysed the technique and materials used for the portrait and concluded it was in fact the work of one artist, with experts agreeing it was a work by Freud, completed around 1939.