Former Olympic cycling champion Samuel Sanchez was provisionally suspended Thursday after failing an out-of-competition doping test.
The International Cycling Union said the Spanish rider for BMC Racing tested positive for a growth hormone releasing peptide in a sample taken on Aug. 9. Sanchez has the right to request a "B" sample.
Sanchez won the gold medal in the road race at the Beijing Olympics in 2008. He was due to race in the Spanish Vuelta, which starts Saturday.
His BMC team announced that it was provisionally suspending Sanchez until the results of the "B" sample are tested.
"BMC Racing Team is extremely disappointed to share this news on the eve of the Spanish Vuelta," the team said.
Loic Vligen will replace the 39-year-old Sanchez on BMC's team for the Vuelta.