Grand Canyon National Park rangers said they received an emergency call to an area of the Colorado River near Deer Creek Falls on Tuesday but attempts to revive Kenneth Reece, a 77-year-old from Tasmania, were not successful.

Mr Reece was pulled from the river by other members of his tour and CPR was initiated.

Park rangers and the Coconino County Medical Examiner Office are investigating his death.

The rescue team recovered his body with the park's helicopter.

Park rangers issued a warning to Grand Canyon visitors.

They cautioned swimming in the Colorado River is different from swimming in pools, with the water changing from shallow to deep in just a few steps.

There are also swift, strong currents, waterfalls, cold temperatures and underwater hazards such as trees and boulders that can overcome the strongest swimmers.

Australian Associated Press