DOCTORS have ordered no visitors as concern deepens for the health of Hong Kong's leading triathlete Ian Rayson, who is suffering from a mysterious illness. Friends and associates have been turned away as they tried to pay the territory's number one triathlete a visit at the Prince of Wales Hospital. Doctors have ordered no visitors for the 32-year-old for the sake of the athlete, whose condition is reported to be deteriorating. Tests are being run on the former British triathlete and doctors are still unable to diagnose his illness although it was definitely brought out by severe dehydration after competing in last week's Singapore Triathlon. Rayson finished second behind world junior champion Spencer Smith of Britain in Singapore but was rushed to hospital a day later. His condition has worsened since the race. He was five minutes behind the winning time of one hour and 53 minutes, but finished four minutes ahead of third-placed Malaysian Mohamed Rassini. Rayson had complained the weather in Singapore was too hot and humid. Rayson is also suffering from pain in the lower part of his pelvis and has difficulty walking. Female triathlete Kim Isherwood experienced similar problems a few years ago when a virus scuppered her training for months. She will be one of several top local triathletes, who will compete in the last race of the Asian triathlon series on Sunday in Subic Bay, the Philippines.