Ross and Naess were married 13 years and had two children

Norwegian billionaire Arne Naess, 66, died as he tried to abseil down a cliff after turning back due to thick mist.

Mr Naess is reported to have declined suggestions that he take a local climber with him up the ridge in the Franschoek mountains near Cape Town.

Mr Naess, who was married to Ross for 13 years, was an experienced climber and had climbed Mount Everest in 1985.

He was in South Africa visiting Johan Rupert, the son of South African business tycoon Anton Rupert.

He set off to go climbing alone early on Tuesday.

(Mr Rupert) turned away for less than a minute and when he looked again Mr Naess's ropes had disappeared Kevin Tromp Wilderness Search and Rescue

Wilderness Search and Rescue spokesman Kevin Tromp said Mr Rupert had been watching Mr Naess's progress through binoculars.

"Mr Naess telephoned his host Johann Rupert shortly before 12:30pm (1030GMT) to tell him that there was thick mist and that he would be descending the cliff," Mr Tromp told French news agency AFP.

"Mr Rupert looked through his binoculars and saw Mr Naess descending. He turned away for less than a minute and when he looked again Mr Naess's ropes had disappeared."

Rescuers found Mr Naess's body in thick bush in a high part of the mountain.

Loose grip

Mr Tromp said the Norwegian tycoon had "wanted to climb a ridge that had never been climbed before and be back before lunch".

He said the ridge was not a difficult one, but was "not on a clean line".

"Mr Naess fell while he was abseiling. His camming device, which locks in the crags of rocks, had come loose," he said.

Mr Naess married Ross in the 1980s and the couple had two children before they were divorced in 2000.

He leaves seven children, including two with his partner, Norwegian Camilla Astrup.

His uncle, Arne Naess senior, was also a mountaineer.