Armstrong admits doping to Oprah: 'I was a bully, but blame it on my fight with cancer'

He admitted that, defending himself from charges that he'd used banned substances in his races, he became a "bully." He blamed his battle with testicular cancer for changing his attitude.

"I was always a fighter," Armstrong said . "Before my diagnosis, I was a competitor, but not a fierce competitor. Then I said I will do anything I need to do to survive. Then I brought that ruthless, win-at-all-costs attitude into cycling."

Oprah's interview with Armstrong - a YouTube clip is shown here - was expected to boost the fortunes of Oprah's struggling network. Oprah said the interview was "the biggest she had ever done."

Oprah brought up people from Armstrong's past who had made allegations against the cycling star- and whom he sued over their claims against him. One was Betsy Andreu, wife of ex-teammate Frankie Andreu, one of the first to allege Armstrong had once admitted to using banned substances.

Armstrong admitted he had spoken to Andreu by phone for 40 minutes to apologise. He would not discuss the content of the phone call but challenged the truthfulness of Andreu's charges against him.

"If they said 10 things and eight of them are right and two of them are false, then I have every right to go after them," Armstrong said. Oprah appeared incredulous, said the Los Angeles Times.

Later Andreu told Anderson Cooper on CNN: "I'm really disappointed. 'You owed it to me, Lance. And you dropped the ball.'"

Armstrong's former masseuse, Emma O'Reilly, also testified about Armstrong's doping habits.

"She's one of the people who got run over and got bullied," Armstrong said.

"You sued her," said Winfrey .

"To be honest, Oprah, we sued so many people... I'm sure we did," Armstrong replied. "I've reached out and tried to make amends on my own."