MOSCOW (Reuters) - Prosecutors in Russia want to ban the award-winning satirical U.S. cartoon South Park, calling the series "extremist" after receiving viewer complaints, a spokeswoman said Monday.

South Park, a cartoon aimed at adults and featuring a group of nine-year olds in a Colorado ski town, has courted controversy from its 1997 debut, parodying celebrities, politicians, religion, gay marriage and Saddam Hussein.

Basmanny regional prosecutors office spokeswoman Valentina Titova said investigators filed a motion after deciding an episode broadcast on Moscow television station 2x2 in January "bore signs of extremist activity."

"In accordance with the conclusions made by experts from the court investigations committee, a claim has been filed against 2x2 for its broadcast of an episode of South Park," Titova said.

South Park has won two Emmy Awards and was first shown on the U.S. Comedy Central network. It is dubbed into Russian and rebroadcast on local networks, including 2x2, a channel which broadcasts animated series in Moscow and St Petersburg.

A representative for 2x2 was not immediately available for comment.

The Russian Union of Christians of Evangelical Faith had asked prosecutors to ban South Park after it said 20 experts had studied the show for its effect on young viewers.

The group's leader, Konstantin Bendas, said "South Park is just one of many cartoons that need to be banned from open broadcast...as it insults the feelings of religious believers and incites religious and national hatred."

"Our complaint is against a lot of cartoons, but this one was from South Park season three, episode 15," he said.

The episode, called "Mr. Hankey's Christmas Classics" on the cartoon's website www.southparkstudios.com, first aired in December, 1999, and features the cast singing Christmas carols.

"It's one thing if they are on cable TV and viewers pay money and make a conscious choice. But young children should not be able to turn on the TV after school and watch this. They need to be defended," Bendas said.

Russia passed a 2006 law widening the definition of extremism to include "the abasement of national dignity" and "inciting religious and national hatred," which backers say was needed to stem a wave of violence aimed at ethnic minorities.