By Jonathan Fowler
The Associated Press

Sir Peter Ustinov, a brilliant wit and mimic who won two Oscars for an acting career that ranged from the evil Nero in Quo Vadis to the quirky Agatha Christie detective Hercule Poirot, has died in Geneva. He was 82.

Ustinov, whose talents included writing plays, movies and novels as well as directing operas, also devoted himself to children for more than 30 years as a goodwill ambassador for UNICEF.

He died of heart failure Sunday night in a clinic near his home overlooking Lake Geneva, his close friend Leon Davico told the Associated Press.

"He was a great man. He was a human being. He was a unique person, someone you could really count on," said Davico, a former UNICEF spokesman.

Born in London on April 16, 1921, the only son of a Russian artist mother and a journalist father, Ustinov claimed also to have Swiss, Ethiopian, Italian and French blood.

Ustinov made some 90 movies and also wrote books and plays. He directed films, plays and operas. His narration of Peter and the Wolf won a Grammy.

Among his film roles were a nomad in the outback who befriends a family in The Sundowners, a one-eyed slave in The Egyptian, Inspector Poirot in Death on the Nile, and Abdi Aga, an illiterate tyrant with pretensions of learning in Memed My Hawk.

Ustinov won best supporting actor Oscars for the role of Batiatus, owner of the gladiator school in Spartacus (1960), and as Arthur Simpson, an English small-time black marketeer in Turkey who gets caught up in a jewel heist in Topkapi (1965).

His Nero - the Roman emperor who presided over the throwing of Christians to the lions - won him a Golden Globe for best supporting actor in the 1951 movie Quo Vadis.

He also won three Emmys: as English lexicographer Samuel Johnson in Dr. Johnson and Socrates in Barefoot in Athens. In A Storm in Summer, his Emmy came for playing an aged Jewish delicatessen owner in Long Island at grips with racial prejudice in the shape of a proud black youth.

He directed, wrote the screenplay and starred in the 1962 movie Billy Budd.

Ustinov left the prestigious Westminster School at 16. He appeared in his first revue and had his first stage play presented in London in 1940, when he was 19.

Ustinov turned producer at 21 when he presented Squaring the Circle shortly before he entered the British army in 1942.

If his plays had a continuing theme, it was a celebration of the little man bucking the system.

Ustinov later became a staunch advocate for UNESCO, the United Nations Educational, Scientific and Cultural Organization. "He never said no to anything UNICEF or the rest of United Nations asked him to do," Davico said.

Ustinov's long service as a United Nations goodwill ambassador led U.N. Secretary-General Kofi Annan to joke that Ustinov was the man to take over from him.

He later set up a foundation dedicated to understanding between people across the globe and between generations.

"I think knowing people is the best way of getting rid of prejudices. When I was young, I was brought up in an atmosphere which was just loaded with prejudices," he said in 2001.

He remained active until close to his death, playing himself in the 2003 TV movie Winter Solstice.

Ustinov was married three times, and is survived by his four children and his third wife.