PAU, France (AP) _ Tour de France rider Alexandre Vinokourov tested positive for a banned blood transfusion after winning last weekend's time trial, prompting his Astana team to pull out of the race.

The positive test of the Kazakh rider, a one-time favourite to win cycling's premier event, dealt a heavy blow to a sport already reeling from a spate of doping scandals.

``Vino has tested positive having to do with a blood transfusion and the team is leaving the Tour,'' team spokeswoman Corinne Druey said, using the rider's nickname.

The positive test took place after the Kazakh rider's victory in the 13th stage time trial on Saturday, L'Equipe newspaper reported on its website.

Vinokourov won two stages this year _ the time trial in Albi and Monday's 15th stage. He is 23rd in the overall race standings. He dropped out of contention for good Sunday after losing 28 minutes 50 seconds to race leader Michael Rasmussen.

L'Equipe said the analysis was conducted by the Chatenay-Malabry lab on the outskirts of Paris. It said two distinctive types of red blood cells were found in the A sample and showed that Vinokourov received a blood transfusion from a compatible donor shortly before the time trial.

A senior French anti-doping official confirmed to The Associated Press that there was a positive test for a blood transfusion taken from a rider at the Tour on Saturday, but said he didn't know the name of the cyclist involved. He said the test found two different types of blood, one from the rider, one from a donor.

The official spoke on condition of anonymity because no official announcement had been made.

Vinokourov has been a crowd favourite along the course route this year. He was injured in a crash in the fifth stage, requiring stitches in both knees.

``With a guy of his stature and class, in cycling's current situation, we might as well pack our bags and go home,'' said British rider David Millar, who came back from a two-year doping ban in the Tour last year.