Gourette, France Tour de France leader Michael Rasmussen was removed from the race by his team after winning Wednesday's stage, the biggest blow yet in cycling's doping-tainted premier event.
"Michael Rasmussen has been sent home for violating (the team's) internal rules," Rabobank team spokesman Jacob Bergsma said.
The expulsion, which Bergsma said was ordered by the Dutch team sponsor, was linked to "incorrect" information that Rasmussen gave to the team's sports director over his whereabouts last month.
Rasmussen, who also has been suspended from the team, missed random drug tests May 8 and June 28, saying he was in Mexico. But a former rider, Davide Cassani, said Wednesday that he had seen Rasmussen in Italy in mid-June.
Bergsma said the team had not decided yet whether its other riders would take the start today in Pau. The 33-year-old Danish rider, who's led since July 15, looked set to win the race which ends on Sunday in Paris.
As Rasmussen raced toward what would have been his first Tour victory, Tour officials questioned why he was allowed to take the start on July 7 in London, England.
"We cannot say that Rasmussen cheated, but his flippancy and his lies on his whereabouts had become unbearable," Tour director Christian Prudhomme said.
The leader of cycling's governing body applauded the decision.
"My immediate reaction is, why didn't they do this at the end of June, when they had the same information," Pat McQuaid said. "The team decided to pull him out; I can only applaud that. It's a zero-tolerance policy, and it's a lesson for the future."
With Rasmussen out, Spanish rider Alberto Contador of the Discovery Channel team moved into the race lead.
In recent days, Tour riders had voiced their skepticism about Rasmussen, and fans booed him at the start of Wednesday's stage.
After the Tour's upbeat start in London, when millions of spectators lined the streets, bad news - nearly all of it related to doping - quickly claimed the spotlight.
German rider Patrick Sinkewitz crashed into a spectator then was revealed to have failed a drug test in training before the race began.
On Tuesday, Alexandre Vinokourov was sent home after testing positive for a banned blood transfusion, and his team pulled out of the race. Wednesday, it happened again when the Cofidis squad confirmed its rider Cristian Moreni of Italy had failed a doping test, prompted the withdrawal of the entire squad.