Lucian Freud slips into view

The artist Lucian Freud made a rare foray into public last night, allowing himself to be photographed in front of one of his own paintings.

Freud, 85, put in an appearance at a party held in his honour, ahead of the auction of his work Naked Portrait with Reflection, which he painted in 1980.

The painting is expected to fetch between £10 million and £15 million when it comes up for auction at Christie's in London at the end of the month.

With interest in Freud's work at an all-time high, it could easily go for more. It could even break the world record for a painting by a living artist, set only last month in New York by Freud when his Benefits Supervisor Sleeping sold for £17.2 million.

That was bought by Roman Abramovich, the oligarch and Chelsea owner, who is establishing his own art gallery in Moscow. Naked Portrait with Reflection, which was bought for £2.8 million by an anonymous bidder in 1998, is likely to be another target for Abramovich, which will help to push the price up further still.

Christie's took the unusual step of hosting a party for Freud and his painting at Mayfair restaurant Automat. Among those at the party was the actor Joseph Fiennes, Lord Linley and former Clash guitarist Paul Simonon. Publicity-shy Freud was last spotted at the recent opening of a show of paintings by Simonon.

Naked Portrait with Reflection is described by Christie's as "one of the most valuable and important postwar works to come up for sale". Also in the auction on 30 June will be a previously unseen Francis Bacon which is expected to sell for £10 million.

Pilar Ordovas, head of post-war and contemporary art at Christie's, said: "The growing demand for works by Freud and Bacon has seen them recognised as two of the most talented, influential and valuable artists of the late 20th century."