Eartha Kitt, the American singer and actress known for her "sex kitten" image and opposition to the US war in Vietnam, has died of colon cancer.

The artist passed away on Thursday at the age of 81.

Kitt had been diagnosed with cancer two years ago and was being treated in New York.

During her career, Kitt was blacklisted in the US for her opposition to the Vietnam war and went into self-imposed exile in Europe in the 1960s, only returning to the US in 1974.

Kitt famously said at a luncheon at the White House in front of Bird Johnson, the wife of the US president: "You send the best of this country off to be shot and maimed... No wonder the kids rebel and take pot."

Kitt described herself as a "sex kitten", while Orsen Wells, the 1930s actor-director, said she was "the most exciting women alive".

"I do not have an act. I just do Eartha Kitt," she told one British newspaper earlier this year.

"I want to be whoever Eartha Kitt is until the gods take me wherever they take me."

Andrew Freedman, her long-time friend and publicist, said: "She had been performing until two months ago... We had dates booked through 2009."

Emmy winner

Kitt grew up on a deprived cotton plantation in a segregated South Carolina, but by the age of 20 had toured the world having started out with the Paris-based Katherine Dunham Dance.

The mixed-race singer performed C'est Si Bon and Old Fashioned Girl and a cover of Edith Piaf's La Vie en Rose.

Fans admired her portrayal of Catwoman in the US TV series Batman in the 1960s, and she had acted alongside Nat King Cole in 1958's St Louis Blues and Sidney Poitier in The Mark of the Hawk in 1957.

In 2000 she voiced the character Yzma in The Emperor's New Grove, a Disney animation, and three years later acted in the musical Nine on Broadway.

Her work continued towards and into her eighth decade with the sequel and TV series of The Emperor's New Grove, theatre work and cabaret shows. 

Kitt won two Emmy television awards and was nominated for two Tonys and two Grammys.

She was married for five years in the 1960s to Bill McDonald, a real estate developer. The union produced one daughter, Kitt.