LONDON - The Twitter Olympics has begun, and Greek triple jumper Voula Papachristou is the first casualty.
Papachristou has been expelled from the London Games by Greece for her Twitter posts commenting on African immigrants and expressing support for a far-right party.
Papachristou, a 23-year-old from Athens, was to compete in her first Games.
The IOC has strict guidelines on what athletes can say in social media. This is the first case of an athlete being expelled from an Olympics for social media use.
The tweet that got Papachristou in trouble was posted July 22: "So many Africans in Greece at least West Nile mosquitoes will eat homemade food"
Fifty-four people marked it as a "favorite" on Twitter.
Papachristou apologized on Twitter and Facebook, saying that her comment was a joke: "I would like to express my heartfelt apologies for the unfortunate and tasteless joke I published on my personal Twitter account. I am very sorry and ashamed for the negative responses I triggered, since I never wanted to offend anyone, or to encroach human rights.
"My dream is connected to the Olympic Games and I could not possibly participate if I did not respect their values. Therefore, I could never believe in discrimination between human beings and races."
The Hellenic Olympic Committee said in a statement Wednesday that Papachristou is "placed outside the Olympic team for statements contrary to the values and ideas of the Olympic movement."
Papachristou is in Athens. The committee says she was to travel to London shortly before the track events start Aug. 3. She was 11th at the European Championships in 2011.
Word spread throughout the Olympic Village, where most of the athletes will live during the Games.
U.S. swimmer Ricky Berens, who posts on Twitter, said he hadn't read Papachristou's tweets, but he had heard of the athlete's expulsion.
"If you post something racist, I would expect there would be some sort of punishment," Berens said. "That's probably a big 'No, no, no.'"
With so many athletes tweeting, he wasn't really surprised by the news.
"I'm sure there will be a lot of warnings handed out," he said.
"You always have to think through what you're going to tweet - are you allowed to, would they appreciate it?"
U.S. fencer Tim Morehouse, a silver medalist at the 2008 Beijing Olympics, said the expulsion will serve as a guide for other athletes.
"When you hear stories like that, you're sort of learning the line of what you can present and what you can't," Morehouse said.
By Roxanna Scott