According to a report broadcast by French TV station Stade 2, the UCI (cycling’s governing body) obstructed a police investigation into mechanical doping during the 2015 Tour de France. French police had received tips from multiple sources that two cyclists had been using illegal motors in their bikes during the early stages of last year’s Tour, and conducted surveillance on Stages 7–9. But their main target, a bike company engineer, never showed up, reportedly because a UCI official tipped him off.
Source: Gizmodo – Report: Cycling Official Covered Up Motorized Doping At The Tour De France