"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.
"I would like to apologize to all my friends and fellow athletes, who I may have insulted or shamed, the National Team, as well as the people and companies who support my athletic career. Finally, I would like to apologize to my coach and my family."
In earlier posts on her Twitter feed, Papachristou posted a picture of herself with other Greek Olympic athletes.
She also retweeted posts from Golden Dawn, a far-right wing Greek political party, and its spokesman Ilias Kasidiaris. Kasidiaris received international attention in June when he appeared on a Greek news program with two female left-wing politicians. During a debate, he threw water at one of the women and smacked the other three times across the face.