So, Lance Armstrong has admitted he used performance-enhancing drugs, that he lied repeatedly and bullied people.

The next question that needs answering is how is the the disgraced world champion cyclist worth? Ahead of yesterday's telecast of his interview with talk show icon Oprah Winfrey, the figure of between $100 million and $125 million has been widely circulated.

It's the range often cited, without attribution, by such mainstream media as the New York Times, USA Today and the Wall Street Journal. But senior editor Kurt Badenhausen of Forbes magazine said it's difficult to work out how rich he is, given that he holds no big stakes in publicly listed companies, no longer races for prize money and has lost lucrative sponsorships.

Forbes, famous for its rich lists, estimated Armstrong's net worth at $28 million back in 2005, the year he began his four-year hiatus from cycling, and $20 million in 2009, when he made his Tour de France comeback.

In more recent years, Badenhausen told AFP, Armstrong has probably been earning around $15 million a year from sponsors, public appearances and speaking fees.