Andreu, whose husband Frankie rode with Armstrong, had testified in the US Anti-Doping Agency's case that triggered the Texan's fall from grace.

She said she had heard the 41-year-old confess to doctors treating him for testicular cancer that he had taken performance enhancing drugs.

Armstrong has always denied the incident took place and when asked about it by Winfrey he declined to provide a straight answer.

"He could have come clean, he owed it to me, he owed it to the sport that he destroyed," said Andreu. "The hospital is where it all started. If he wants a shot of redemption here, he's dropping the ball.

"I was willing to give him a chance and that's how he responds?" an emotional Andreu told CNN.

Armstrong finally confessed to using performance enhancing drugs during his cycling career on Thursday, admitting he cheated to win all seven of his Tour de France titles.

Describing himself as a "bully" and a "deeply flawed character", Armstrong ended years of denials by revealing his darkest secrets in an interview with talk show host Winfrey recorded at his hometown of Austin, Texas three days earlier.

Armstrong told Winfrey that while he was the lead rider, he did not decide who made the team.

"That's a bunch of crap," Andreu snapped.

"Lance can redeem himself but only if he comes clean to the USADA and WADA because there is no way he conducted the biggest fraud in sports history on his own," she added.

Armstrong agreed that he had attacked Andreu after she came forward with her testimony, telling Winfrey that he had called her "crazy" and a "bitch", but adding with a smile he had never called her "fat".