Almost 20 years ago, I was enthralled by the Lance Armstrong story. His best selling book, It’s Not About the Bike, told the extraordinary tale of the cancer survivor who returned to win the world’s toughest cycle race, the Tour de France.

Back then, I was a modest cyclist (I still am) with dreams of cycling the length of Great Britain, Land’s End to John O’Groats. I was inspired by Armstrong’s story, especially his dedication to training. Yes, I knew all about cycling’s sordid relationship with drugs, notably the 1998 Tour de France’s Festina affair. (Paul Kimmage lifted the lid on this culture in Rough Ride.) But I believed the Armstrong line: he was the most tested cyclist in history. And every one had shown him to be clean. Karen and I followed Armstrong’s annual progress in Le Tour. I wore the US Postal team kit on several cycling holidays.

His second book, Every Second Counts, described Armstrong completing a gruelling climb of Hautacam in training for the Tour, in pouring snow and sleet. On reaching the top of the Pyrenees climb, Armstrong insisted on doing it again as he hadn’t mastered the climb. That determination seemed to explain how Lance won seven Tours de France against talented rivals like Jan Ullrich.

But not everyone was convinced. David Walsh of the Sunday Times was suspicious from Armstrong’s first Tour win in 1999. Walsh explains his scepticism in his book about his pursuit of the truth, Seven Deadly Sins. It started with the time trial in Metz. In his four pre-cancer Tours, Armstrong was remarkably consistent, finishing just over six minutes behind the winner. Yet in 1999, he was the emphatic victor. It was a similar story in the mountains. He’d never finished better than 39th on a mountain stage, and was usually much further down the pack. But all that changed in 1999. On the climb to Sestriere, he talked about bumping into the motorbike pillion riders. He certainly left his rivals behind.

Walsh could see no other explanation but that Armstrong was doping. The 1999 edition was meant to be the Tour of Renewal after the Festina scandal the previous year, which exposed cycling’s sordid addiction to performance-enhancing drugs. Yet the average speed actually increased over 1998’s flawed race.

David Walsh went on to write L.A. Confidentiel, an expose of Lance Armstrong, with French journalist Pierre Ballester. It was published in France to avoid Britain’s punitive libel laws. Armstrong dismissed Walsh as a troll, and bullied anyone who dared question his honesty or claim his seven Tour wins had been secured through cheating.

It seems incredible now that Lance Armstrong acted so brazenly knowing he had been cheating all along. In Every Second Counts, he says he was looked forward to total exoneration from the doping claims. He quotes his agent Bill Stapleton saying, “[Armstrong] doesn’t take drugs, okay? I will stake my entire career on it.” All lies.

David Walsh graphically describes the impact Armstrong’s strong-arm tactics had on those who spoke out. It’s clear that he has the highest admiration for Emma O’Reilly, Betsy Andreu, Stephen Swart and Greg Lemond, who put their livelihoods and reputations on the line doing the right thing.

The end came in October 2012. Armstrong did not contest the United States Anti-doping Agency’s verdict that he was a serial cheat. Ironically, the truth may never have been confirmed had the ego-driven Armstrong not come out of retirement in 2009 to try to win another Tour de France.

David Walsh and the other whistle-blowers had been vindicated. The sadness is that the cycling establishment and the Tour de France organisers refused to clean up the sport. The 1999 Tour and those that followed were a continuation of the shameful drug fuelled cheating of the Festina affair. Walsh deserved all his plaudits as did the Sunday Times: this was journalism at its best. Persistent and brave. Exposing wrong doing and fraud.

Walsh movingly talks about his 12 year old son John, killed in a road accident in 1995. John would always ask the questions no one else would think of posing. Like, what did Mary and Joseph do with the gold from the three wise man? His school teacher said no one else had asked that one in the 30 years she’d been teaching the nativity story. John’s father followed that example, and kept posing the questions that Lance Armstrong didn’t want to hear. At last, after 13 long years, Armstrong admitted he’d been lying all along. That admission came on John’s birthday. A gift for the devoted father who always asked the awkward questions.