Image 1 of 5 Thomas Voeckler (Direct Energie) (Image credit: Getty Images) Image 2 of 5 Johan Bruyneel with Lance Armstrong on the Champs Elysees in 2002 Image 3 of 5 Thomas Voeckler (Direct Energie) talks to media after the Tour de Yorkshire press conference (Image credit: Tim de Waele/TDWSport.com) Image 4 of 5 It wouldn't be a Tour de France without Thomas Voeckler in a breakaway Image 5 of 5 Lance Armstrong looks on upon his arrival in Rodez, southwest France, after riding a stage of The Tour De France for a leukaemia charity

Thomas Voeckler has spoken out about mechanical doping, saying he is convinced that he raced against riders using hidden motors and that he wouldn't be surprised if Lance Armstrong had cheated in such a way.

The Frenchman called an end to his 17-year career at the end of the 2017 Tour de France and is preparing to make his debut as a pundit for French state broadcaster France Télévisions next month.

Voeckler rode through a troubled era in cycling as the sport failed to clean itself up in the wake of the 1998 Festina Affair. He has always denied doping himself but there were a number of cases involving his contemporaries – including Armstrong – and now, having initially been sceptical, he believes there was doping of the mechanical sort, as well as the chemical.

"At first, when I heard people talking about it, I laughed. I said to myself, 'What have they found now to damage cycling?'" Voeckler told French newspaper, Le Parisien.

"Later, seeing certain reports, I was convinced that some have taken us for fools and used a motor."

The issue of mechanical doping has become increasingly prominent over the past few years. Sophisticated technology is clearly in existence and many suspect it has been used in the sport's biggest races. The UCI has stepped up its testing to include scans using a tablet device – though question marks have been raised over its effectiveness – and David Lappartient made the issue a key part of his campaign as he defeated Brian Cookson to become the new UCI president in September.

Beyond amateur cyclists, Femke van den Driessche is so far the only rider to have been caught with a hidden motor. The Belgian cyclo-cross rider received a six-year ban from the UCI in 2016 after a motor was discovered in one of her bikes at that year's cyclo-cross Worlds.

"In my opinion, there's no more of it since the tests were put in place," said Voeckler. "It's a form of doping that is not complicated to eradicate."

Voeckler was also asked by Le Parisien if he believed Lance Armstrong had used a hidden motor. Armstrong was stripped of his seven Tour de France titles – three of which were won in the presence of Voeckler – after admitting to using EPO and other banned substances, but there are suspicions that he may have doped mechanically, too. Armstrong has flatly denied such allegations.

"Did Armstrong use it? With him, I'd no longer be shocked by anything," said Voeckler.