Walsh joined The Sunday Times in Ireland in 1996 and began working on the story about doping in professional cycling shortly after moving to England in 1998.
Walsh revealed in the Sunday Times in 2001 after a two-year investigation that Armstrong was working with the controversial Italian doctor Michele Ferrari.
[8] Before Winfrey did the interview, Walsh's Sunday Times bought a full-page ad in the Chicago Tribune—Winfrey lives in Chicago—to suggest 10 questions she should ask.
[11] On 29 January 2013, the World Anti-Doping Agency (WADA) said it is "dismayed" by the way cycling's global governing body has handled the fallout from the Lance Armstrong affair and accused it of being "deceitful" and "arrogant".
In 2017, Walsh gave a character reference for former sports journalist Tom Humphries during his trial for child molestation.