In his Holland Park studio Lucian Freud is working night and day, seven days a week, on four new paintings.

As soon as the first one is finished anyone who wants to will be able to buy it, his gallery said yesterday. They just might need £10 million.

The 85-year-old British painter became the world’s most expensive living artist at auction this week when his Benefits Supervisor Sleeping sold at Christie’s in New York for $33.6 million (£17.2 million).

The sale meant that the close friends, family members and bookmakers who are some of the largest owners of Freud’s work woke up on Wednesday morning with an urgent need to re-evaluate the assets hanging on their walls.

When they bought, paintings fresh from the artist’s studio were available for a few thousand pounds. Not any more. Freud’s ascent to the pinnacle of the contemporary art market has been dizzyingly rapid.

Earlier in his career he often lived off cash handouts from his more successful friend, Francis Bacon.

In the 1980s his paintings frequently failed to sell at auction and the record price for his work did not reach £500,000 until 1994, by which time he was already into his seventies.

William Acquavella, an art dealer from New York, snapped Freud up in 1992 when others thought that his work was not commercial.

Mr Acquavella said: “He showed me the paintings he was working on at the time, of Leigh Bowery [a large Australian performance artist]. A lot of people were put off by them being male nudes but I thought they were so strong it wasn’t going to matter.” The Acquavella Gallery has represented Freud ever since, playing an instrumental role in broadening his appeal in the United States and selling to collectors as far afield as Indonesia, South America, Australia and Russia.

“I do try to keep the prices down but the auctions have brought them to a new level,” Mr Acquavella said. “Another painting of the same significance as Benefits Supervisor Sleeping, if you got it now, would probably be around $20 million.”

There is a waiting list for Freud’s work, consisting of about eight or nine international high-rollers who are occasionally privileged to visit Freud in his studio. However, anybody can approach the gallery if they have enough money.

“Get in touch, we like to start new collectors,” Mr Acquavella said. “There are three types of people who buy: the people who buy for an investment, the people who buy because they love art and the people who do it to keep up with the Joneses. There are big spenders in all three categories.”

“It’s not a mini-auction. Some people want a portrait, others want a nude. Whoever’s in first place on the list gets first look and they won’t necessarily buy what we show them.” Mr Acquavella refused to divulge how much of each sale the artist keeps but added that Freud is uninterested in money. Pilar Ordovas, head of the postwar and contemporary department at Christie’s in London, said: “He says himself that there was a time when it was difficult for him to sell his works. Most of them were bought by close friends, family and bookmakers who he bet on the horses with. They made a commitment at the time because they loved the work.”

Now they have to decide whether they still love it enough to resist the millions of pounds it sells for.

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