Competitors assemble for the Motatapu race today. Photo: Supplied
Police were notified about 9.30am today, and part of Motatapu Rd was closed for a short time.
Event organisers said they were saddened by the death at Glendhu Bay.
"The Motatapu team worked closely with the emergency services and continue to assist. We would like to offer our deepest condolences to the bereaved family."
The death has been referred to the Coroner.
Close to 4000 mountain bikers, runners and walkers took part in the Motatapu, the country's largest off-road sporting event, in Wānaka and Arrowtown today.
