The 2008 Olympic road race champion Samuel Sánchez has tested positive for a growth hormone-releasing peptide and has been withdrawn from the Vuelta a España, the UCI has announced.

The 39-year-old, who won his gold medal in Beijing, rides for BMC Racing and has been provisionally suspended after the failed drug test, cycling’s world governing body added.

A UCI statement said: “The Union Cycliste Internationale announces that Spanish rider Samuel Sánchez González was notified of an adverse analytical finding (AAF) of GHRP-2 in a sample collected in the scope of out-of-competition control on 9 August 2017.

“The doping control was planned and carried out by the Cycling Anti-Doping Foundation, the independent body mandated by the UCI, in charge of defining and implementing the anti-doping strategy in cycling.

“The rider has the right to request and attend the analysis of the B sample. In accordance with UCI anti-doping rules, the rider has been provisionally suspended until the adjudication of the affair. At this stage of the procedure, the UCI will not comment any further on any of these matters.”

Growth hormone has been shown to reduce fat, increase lean body mass and improve aerobic performance.

Sánchez was second at the 2010 Tour de France, behind Luxembourg’s Andy Schleck, and has won stages at the Tour and the Vuelta. He had been listed to start the Vuelta in Nimes on Saturday but has now been withdrawn and suspended by BMC Racing.

A statement from the Swiss-American team said: “In accordance with BMC Racing Team’s zero tolerance policy and UCI regulation, Sánchez has been provisionally suspended with immediate effect. Until the results of the B sample are provided, no further action will be taken.

“All riders and staff are held to the highest ethical standard and BMC Racing Team is extremely disappointed to share this news on the eve of the Vuelta a España. Loïc Vliegen will replace Sánchez at the Vuelta.”