LONDON - British figurative painter Lucian Freud, whose uncompromising portraits made him one of the world's most revered and coveted artists, has died aged 88.

His long-time New York art dealer William Acquavella said the grandson of Sigmund Freud and brother of British television personality Clement Freud had died at his home in London on Wednesday night after an unspecified illness.

Impressionist art expert David Norman holds artist Lucian Freud's "Self Portrait" at Sotheby's before its preview exhibition of highlights from its upcoming London sale of Impressionist Modern and Contemporary art in New York in this January 10, 2011 file photo. [Photo/Agencies]

"My family and I mourn Lucian Freud not only as one of the great painters of the 20th century but also as a very dear friend," the dealer said in a statement.

"As the foremost figurative artist of his generation he imbued both portraiture and landscape with profound insight, drama and energy.

"In company he was exciting, humble, warm and witty. He lived to paint and painted until the day he died, far removed from the noise of the art world."

Whatever he thought of the art world, Freud was very much its darling towards the end of his life.

His "Benefits Supervisor Sleeping", a 1995 portrait of a nude, obese woman asleep on a sofa, fetched $33.6 million at Christie's in 2008, a new auction record for any living artist.

The buyer was widely reported to be Russian billionaire Roman Abramovich.

He tended to paint people he knew -- family, friends and fellow artists, but was also famously commissioned to depict Queen Elizabeth.

The resulting portrait, an unflattering portrayal of a severe-looking monarch painted in 2001, divided the critics, with Arthur Edwards, photographer for the Sun tabloid, saying: "They should hang it in the kharzi (toilet)."

Freud was born in Berlin in 1922 to a well-off German family who fled the Nazis for Britain in 1933 and became British citizens in 1939.

Freud went to several schools but is said to have attended few classes.

"I was very solitary. I hardly spoke English. I was considered rather bad tempered, of which I was rather proud," he once said.

Freud attended a string of art colleges and had a brief spell with the merchant navy before turning to art and staging his first exhibitions in the 1940s.

The artist had a string of relationships and is believed to have left behind many illegitimate children.