Lance Armstrong's explanation that he used performance-enhancing drugs to create "a level playing field" in cycling has been described by the head of the World Anti-Doping Agency as "a convenient way of justifying what he did - a fraud."

WADA president John Fahey told The Associated Press in a telephone interview on Friday that Armstrong's assertion in the Oprah Winfrey television program that he wasn't cheating when he took part in doping through his seven Tour de France wins "gives him no credibility."

Fahey adds: "He was wrong, he cheated and there was no excuse for what he did."

The WADA chief said if Armstrong "was looking for redemption, he didn't succeed in getting that."