Hans Snook might be a fan of colonic irrigation, feng shui and alternative health therapies, but he mixes his commitment to cleaner, spiritual living with a good dose of down-to-earth hedonism.

The former boss of mobile phone group Orange is not sitting in the Diagnostic Clinic he has just opened in London's West End but down the road in a café, drinking black coffee and smoking fags. With his collarless white shirt undone down his bronzed chest, a sparkling Rolex on one wrist and a gold bracelet on the other, the 55-year-old looks ready for a Caribbean cruise rather than for the promotion of his latest venture.

Relaxed he may appear, but he admits to being a bit of a workaholic on the sly and certainly can put on a dynamic show if he needs to. I remind him of a multimedia presentation he gave at the Albert Hall for an annual gathering of the Institute of Directors some years back.

He appeared supremely confident with his flashing lights, mood music and clever soundbites. It was at the height of his power as a bigwig at Orange, when he had turned a struggling telecommunications entrant into a sector leader while making himself an estimated £45 million sterling (€65 million) in share options into the bargain.

"I actually don't like public speaking," he says. "It's the one thing that really stresses me out. It makes me nervous. For one, you have to prepare what you are going to say... if I speak off the cuff I tend to wander off the point a bit, and anyway I feel a great obligation not to be boring and come up with something new."

In fact, talking is something that Mr Snook does with consummate ease - at least in private - which could be fitting, given that one of his other jobs is non-executive chairman of Carphone Warehouse while he remains a chairman of Orange's joint venture in Thailand, PT Orange.

Mr Snook - the name, incidentally, is British although he is half German, hence the Christian name - is up from his Kensington home to talk about the Diagnostic Clinic, which claims to offer a "unique concept in healthcare" that focuses on prevention as much as on cure. The £6.5 million centre provides a variety of orthodox and complementary diagnostic tests and screens that provide a more profound analysis of a customer's health than that given by most annual private health insurance checks.

And that is at the centre of the new enterprise. Mr Snook hopes the big City firms - the investment banks and others - will use the Diagnostic Clinic for ensuring the health of their employees.

But is the conservative Square Mile ready for the world of homeopathy, acupuncture and colonic irrigation? "We actually don't provide any of these services, but we do use complementary medical tests and we are able to refer people to those we regard as top practitioners," says Mr Snook.

Clearly, he has a huge network of personal contacts in the banking community and says one should not underestimate how open many senior business figures are to new ideas. "When I first talked about opening the clinic there was endless comment in the press about my reference to colonic irrigation. In fact, I don't really use it so much as a fasting process, which I do do occasionally. That is fantastic, and you feel great afterwards."

The funkily designed clinic near Harley Street - carefully vetted by feng shui experts, of course - is a one-off now, but that is not the end of the story. If it is successful, Mr Snook plans to roll out the concept across the UK. He is also looking at spin-off, smaller "pods" just off main shopping streets where the public would be able to obtain diagnostic services using the same mix of orthodox and alternative medicine.

"We think this is part of the key to the future of health systems at a time when the NHS is under pressure. You can't have preventative measures until you can diagnose properly. We believe we could create a virtuous circle [for public health] and we are taking the first step," he says. Health is an issue that has interested Mr Snook for a long time, and he is said to take over a dozen vitamin and other pills a day. His interest in medicine developed by the age of 14.

His life has involved a lot of travel. He was born in Germany of an English father serving during the post-war occupation and a German mother. The family moved to England when he was two and then emigrated to Canada when he was eight. For a year young Snook was sent back to Germany while his father worked in Calgary before he returned to his family and secondary school in Edmonton.

His passion at school was reading, and this continued on to university in British Columbia. The height of flower power it may have been, but as a student Mr Snook was pretty uninterested in drugs, revolutionary politics or even ice hockey. "I smoked a bit of grass then but very little, and I have always had a healthy disdain for politics. It's mainly about power-mongering, and I have never been interested in that."

In his mid-30s he headed off for a year's travel. During this time he became involved in the computer and telecoms business with a Chinese firm in Hong Kong. When that was taken over by Hutchison Whampoa he was dispatched to Britain to spearhead the Orange launch. A couple of ownership changes later, he left with a bagful of loot and nothing much in mind for his future. But his domestic life took a new direction with the end of his 22-year marriage. Since then he has gone "plural", setting up the Diagnostic Clinic with experts from Prince Charles's favourite Hale Clinic and planning a spa in Thailand.

"It's an integrated holistic health centre in Kamalaya on the island of Samui," he says. "I have been planning it with a number of people, including John Stewart, who was a sadhu in India for 17 years but as a sideline has an art gallery in New York. Our third partner is a writer who was named recently by the National Geographic as one of the world's top explorers."

Some believe he is a business visionary but he is orthodox in one respect: he is not interested in ventures that don't make money. His idea of heaven is not meditating up a mountain with a holy man, it's "lying by the pool with a crossword and a nice glass of chardonnay".