WRC.com has the details:
Michael Park, co-driver to works Peugeot driver Markko Martin, has died as a result of injuries sustained in an accident on the final leg of this weekend's Wales Rally GB. The rally has been stopped following the incident on SS15 - the 27-kilometre Margam Park stage, which was the final test of this morning's loop.
"It is with deep regret that the organisers of Wales Rally GB confirm that Michael Park was fatally injured following an accident on SS15," an official statement said. "The next of kin has been informed. The driver of car eight, Markko Martin, is uninjured.