LUCIAN FREUD is probably the most admired figurative artist alive in Britain. So it is no surprise that the nude pictured in his latest self-portrait should be clutching his leg adoringly.

But who is the woman who inspired the artist to create The Painter Surprised by a Naked Admirer, the 50in square painting unveiled today at the National Portrait Gallery? Freud has refused to say and the gallery claims not to know, but readers of The Times can judge for themselves by comparing the doting woman to the artist’s friends and muses.

The most likely candidate is Alexandra Williams-Wynn, 32, a sculptor and student at the Royal Academy who was photographed walking arm in arm with Freud last November.

Ms Williams-Wynn, the daughter of a Welsh baronet, has described herself as a “very good friend” of the artist and has posed as a model for him.

“He likes to paint me,” she said last year. “I don’t really want a fuss being made of the fact a 32-year-old might be with an 82-year-old. I know people are interested but I want to be a will-o’-the-wisp about such things. I am a whimsical person.”

Her ancestor Sir Watkin Williams-Wynn, a baronet, is displayed in the National Museum and Gallery of Wales in Cardiff. He is described by the institution as “perhaps the greatest patron of the arts Wales has ever produced”. His most famous act of patronage was to commission several portraits from Sir Joshua Reynolds, the founding president of the Royal Academy, where Ms Williams-Wynn is enrolled as a student of the RA school. She is said to be taking a year off to allow the artist to complete his study of her.

Sir David, her father and the 11th baronet, confirmed that Freud was using her as a subject but he did not know whether the pair were in a relationship. “All I know is that she is being painted by Lucian,” he said. “It gives her enormous opportunities to study under him and develop her painting before resuming her studies.”

Her description of the artist, to whom she was introduced by friends, as a “fantastic person” also shows that she has a similar admiring attitude as the model.

Ms Wynn-Williams is one of three young women recently linked to the artist. Another candidate is Emily Bearn, 31, Freud’s former lover and a journalist at a Sunday newspaper. She posed in Naked Portrait, unveiled at Tate Britain in 2002, but broke off her relationship with him in 2003. She is pregnant and living with another man.

A third possibility is Verity Brown, 28, who was seen dining with the artist last June. She met Freud through her work at Momart, an art transport and exhibition firm, but has never discussed whether she posed for him.

She also bears the least resemblance to the woman in the portrait, although this does not rule her out. Freud’s portraits always depict a likeness but he often distorts figures. He has never had difficulty in persuading younger women to pose for him. One of his most famous portraits include a life-size likeness of Kate Moss, which sold for £3.5 million at Christie’s in February.

Louise Liddell, who featured in a BBC documentary on the artist, said that she was pleased to pose nude because he had “sexual charisma”.

Although the unveiling of the portrait is seen in the art world as an international event, Freud wanted to display the work at the gallery first. “I like my work to be seen by Londoners,” he said yesterday.

The portrait will be on display until May 8, before being transported to a Freud retrospective in Venice in June. It is part of the gallery’s Self Portrait Renaissance to Contemporary exhibition, which contains a Freud self-portrait painted in 1967. Other artists include Van Gogh, Velázquez and Bacon.