The death of Peugeot's British co-driver Michael Park cast a pall over the Rally of Britain on Sunday.
The final stages were cancelled following the fatal accident and cars headed back to rally headquarters in Cardiff for the formal finish of the 12th round of the world championship with the results uncertain.
On a grim day for the sport, Park's grieving team announced their immediate withdrawal from the event.
That decision would effectively hand Citroen's Sebastien Loeb his second successive title in the most tragic of circumstances, although sources said the Frenchman could also act to ensure that did not happen.
Loeb had been heading for a record ninth win of the season, and first in Britain, until the crash.
Park, 39, from Newent in Gloucestershire, was partnering Estonian Markko Martin who was unhurt in the 15th stage accident. Peugeot said Martin went off the road and hit a tree on the passenger side.
"It is with deep regret that the organisers of Wales Rally GB confirm that Michael Park.. has been fatally injured," a statement said. "Next of kin have been informed."
Rallying has always been a dangerous sport, with spectator safety a particular concern, but fatal accidents have become rare at world championship level.
PEUGEOT MOURN
Park, nicknamed 'Beef', was a highly-experienced co-driver who had worked with former champions Richard Burns and Colin McRae.
Married with two children, he teamed up with Martin in 2000 when the Estonian was rallying a privately-entered Toyota.
They stayed together at Subaru and Ford before moving to Peugeot this year.
The pairing had won five rallies and were the only ones to have scored points in every event this year, starting the weekend fourth in the championship.
Martin, whose team are just six points behind stablemates Citroen in the manufacturers' championship, was in sixth place at the time of the accident.
"A serious accident has left the Peugeot team in mourning," the French carmaker said in a statement.
"Peugeot Sport director Jean-Pierre Nicolas, with the agreement of Mr Frederic Saint-Geours, managing director of Peugeot, has decided as a sign of mourning to withdraw the car of Marcus Gronholm and [co-driver] Timo Rautiainen.
"Peugeot Automobiles and Peugeot Sport would like to express their feeling of extreme sadness and deep emotion to the family of Michael Park."
The governing International Automobile Federation (FIA) also offered their condolences.
Loeb was leading Subaru's Norwegian Petter Solberg by 42.1 seconds after the day's opening Resolfen stage.
Peugeot's Marcus Gronholm, Loeb's closest rival in a championship that has become a foregone conclusion, was in third place and a further 41.8 behind.
Loeb had needed to beat Gronholm by eight points to retain his world championship with four rounds to spare.
Organisers scrapped the end-of-rally champagne celebrations and said the usual post-race news conference has also been cancelled.
