To the outside world he seems to have it all. He is one of the world’s great golfers, has a multimillionaire’s lifestyle, lives with his young family in beautiful houses in England, South Africa and the United States, and travels the world in his private jet. But one day, two years ago, the world fell in on Ernie Els — or so he thought at the time. The South African was told by doctors that his son, Ben, who was 5 at the time, was autistic. And life for Els and his wife Liezl was about to change for ever.

Yet after a period of deep reflection, and not a little self-pity, Els is devoting much of his energy into promoting research and raising public awareness of the condition. “It’s like an epidemic,” Els says. “It’s a complete mystery.” Last week at Wentworth Golf Club in Surrey, where he was competing in the BMW PGA Championship, Els, 39, talked at length about Ben’s condition. As the winner of three major championships, including the Open in 2002, he knows that he is lucky to be able to fund intensive treatment and care for his son — in fact he has moved his family to America, where there are private schools for autistic children — but he is also determined to help others less fortunate than himself.

“There’s a process that every kid will go through,” Els explains. “Crawl at nine months, walk at 12 months, start talking and so on. Then with Ben, we started thinking: ‘Why is he not crawling? Why is he not walking? Why is he not looking me in the eye?’ Things like that. I want to make people aware that you have got to look for the signs, because the earlier [doctors] can start treating the child, the better chance he has to get into mainstream society.

“Ben is quite severely touched by it. He’s coming up to 7 and he can’t say full sentences and has a lot of difficulties.But, thank God, he’s got such a nice nature. He’s a very friendly, very happy, very shy kid and the more loving attention he gets and smiles that he sees, the better. And Samantha, his older sister, is great with him.”

Autism and Asperger’s syndrome belong to a group of conditions that vary greatly. Some sufferers can function as well as anyone else around them, whereas others can be so severely affected that they are unable to take part in normal society. Because of the range of symptoms and their severity, the condition is known as autistic spectrum disorders (ASD). Those affected are likely to be socially unaware, uncommunicative and self-absorbed, unable in many instances to read facial signals or body language.

Els has become a visible and vocal supporter of the charity Autism Speaks, started in the US in 2004 and with a vibrant UK arm, and has set up his own charity — Els for Autism Foundation — with the aim of funding the building and running of a research centre at the Scripps Institute in Florida. In less than a year, he has raised $800,000 (£510,000).

Els says that it is “human nature” to keep people with autism at arm’s length and talks about the toll it can take on a family. Self-pity, isolation, confusion, anger, sadness and fear are just some of the emotions experienced as families seek to come to terms with the future. Some liken the moment they are told to a bereavement. Everything changes. Some estimates in the US put divorce rates among families who have an autistic child as high as 80 per cent. The stresses, and subsequent strains on health, are obvious.

“It hits you really hard,” Els says. “It’s a very emotional thing within the family. Liezl is very strong and I am, too, but for a while we were crossing paths, trying to work out the way forward. We needed to get on to the same path, to move in the same direction.

“I thought that Ben should go to a school for autistic kids. Liezl disagreed and said that she thought he had a chance to get into normal society. So he went to the same school [near Ascot, Berkshire] as his sister, but right away you could see he had no chance. The school was great and allowed us to send a private tutor with him, but he stayed in the same class for two years and then he started getting a little too big. And that’s when we decided that we needed a change.”

That change entailed a move to Jupiter, Florida, where Els could practise golf in good weather all year, play competitively across the States and, more importantly, secure a more intensive form of therapy for Ben than could be guaranteed in Britain. “We are lucky enough to have the money to employ a teacher for Ben and in America they have private schools for autistic kids,” Els explains. “In the UK it’s in the state sector, which is fine, but things do not seem to be moving quite quickly enough. Ben gets private tutoring, heavy one-on-one stuff for hours. You have to give the kid a break, but it’s about seven or eight hours a day just to get him going.”

A typical day includes speech and language therapy and the teaching of the social skills necessary to participate, ultimately, in everyday life, to introduce an element of self-care. It is a slow and painful process. But even in the US, Els points out, there are no high schools for autistic children.

“It shows that even in this day and age, the kid who has autism is forgotten about,” he says. “The feeling is that he’s a waste of time. Just put him in a home and go and visit him now and again. But that says more about society than the child. It’s daft. Ben understands everything we say and is particularly in tune with our emotions, it’s almost a sixth sense. If you are a little bit upset about something, he’s switched on to it. That’s why we have to keep smiling.”

Els says that his son’s condition has given him a new perspective on life. While he still works hard at what he does — in addition to playing, he is now a golf course designer as well as the owner of a vineyard in South Africa — he explains that golf is no longer the be-all and end-all.

“I still put in a lot of work on my game, but caring for Ben and getting the foundation up and running has taken a lot of time and energy,” he says. “Golf is everything, and then the family comes along and that’s special. But when something like this comes into your life, your priorities change.

“Has it made the family stronger? Definitely. We went through a difficult period for a while because of Ben’s problems and the direction we should take. We were unsure because there is no perfect solution and we were going around in the dark. For a long time you are trying to figure out ‘What the hell just happened to my life?’ You feel sorry for yourself and for your kid, obviously, and for your family. But then you realise that this is an opportunity that we have to grab. I’ve still got to play golf, but we want people to know that we are working on the problem. We want them to know the signs they should be looking for and how they are going to deal with it emotionally. We want the guy in the street to know that we have exactly the same problems.”

Among Els’s inspirations is Dan Marino, the former Miami Dolphins quarterback and one of the greatest players in American football history, who set up and has helped to fund a research centre in Miami after his son, Michael, had autism diagnosed at the age of 2. His story is a beacon of hope. Michael has responded so successfully to therapy that he would not now be regarded as autistic.

“I did share Michael’s story with Ernie,” Marino says. “I think it does provide hope for people. The big thing with Michael is that, from the time he was two years old, we started with occupational speech and other therapies. Early intervention is where we were really able to make an impact. That has helped other people with the hope that if you are diagnosed early enough, you have a chance to be successful.”

Just such hope is focusing Els’s attention now. He is determined to build his research facility. “I want to get the scientists together to try to find out what’s going on,” he says. “Whether it’s the food that we’re eating, whether it’s radio waves, whether it’s the shots [vaccinations] kids get, or is it purely genetic? In truth, nobody really knows what the cause is, but it’s virtually an epidemic.

“I believe that kids are born with autism, though, and for some reason the brain is not working properly. If we can find out what’s causing it, that would be a great breakthrough. It’s amazing that it is a mystery when you consider all we know nowadays. In terms of the number of people afflicted it is worse than cancer.

“People will remember me as a major champion. But hopefully when I’m forgotten as a player, I’d like also to be remembered as somebody who took this autism research and did something with it. I think I have a lot of time left. The rest of my life, I’ll be fighting this thing.”

www.autismspeaks.org.uk