The top of the overall standings remained unchanged on the eve of the first mountain stage with Igor Gonzalez Galdeano of Spain leading three-time defending champion Lance Armstrong by 26 seconds.
Wednesday's 147-kilometer ride took the competitors from Bazas to Pau, in the foothills of the Pyrenees, and it was filled with tragedy and controversy.
The fatality occurred in the village of Retgons, 26 kilometers from the start of the stage. Despite attempts by tour officials to warn of the dangers of the huge parade of fast-moving cyclists and motorists that make up the traveling carnival, there has been a long history of accidents.
A 12-year-old boy was killed two years ago.
There were also a number of newspaper reports Wednesday indicating Galdeano, who has worn the leader's yellow jersey since last week's team time trial, was among those suspected of taking a banned substance. Recent tours have been beset by drug problems.
The International Cycling Union released a statement saying that no rider had tested positive this year.
"Following the information published in several newspapers this morning concerning the rider in the yellow jersey, Igor Gonzalez Galdeano, the International Cycling Union (UCI) would like to reiterate the fact that all antidoping tests which have been carried out since the Tour's pre-race medical examinations -- including the test for EPO -- are negative.
"The UCI has confirmed that the riders who used Salbutamol have a medical justification validated by the UCI, as written in its regulations. All these tests are therefore also negative."
Halgand was part of a break that included as many as 16 riders and lasted for most of the stage. In the final five kilometers, Halgand stormed away from others in the group. He held on to cover the distance in 15 seconds more than three hours. He was 27 seconds ahead of countryman Jerome Pineau and 33 seconds ahead of Stuart O'Grady of Australia and Ludo Dierckxsens of Belgium.
The peloton finished three minutes, 57 seconds behind Halgand, but that did not affect the overall frontrunners.
Thursday's critical stage will take the riders to the mountain town of La Mongie, by which time Armstrong is expected to be in front.
Although there has been speculation that Armstrong is not up to the form he displayed in winning the last three tours, chiefly because he finished second in Monday's individual time trial, he is still the overwhelming favorite.
Armstrong leads third-place Joseba Beloki of Spain by almost a full minute and he has already opened significant gaps over the better climbers in the field.