Samples provided by the 27-year-old Italian on October 15 and 16 - stage 12 and 13 of the road race - were found to have contained ostarine.

Ostarine, also known as MK-2866 and enobosarm, is a selective androgen receptor modulator that is illegally sold as a performance-enhancing substance.

Following the adverse analytical findings, Spreafico confessed to Italian police that he had ordered a supplement containing the drug over the internet. 

"The boy confessed that he took this supplement taken on the internet, handed it over, and then the room was checked, and a report was made," Vini Zabù-Brado-KTM general manager Angelo Citracca said, according to La Gazzetta dello Sport.

"There were no 'blitzes' and no drugs, as shown by checks carried out by the doctor. 

"Spreafico took full responsibility."

Spreafico has now been fired from the team, which he joined in August from Androni Giocattoli-Sidermec, and could face a four-year doping ban. 

His offence also fell foul of Italian law, although no Italian professional cyclist has previously been jailed due to doping.

Spreafico, who won the Vuelta a Venezuela in 2018, was making his Giro d'Italia debut after four years as a professional cyclist. 

Britain's Tao Geoghegan Hart claimed victory in the race, which concluded on Sunday (October 25).