In the flesh

s the waiter approaches our table in the elegant dining room of Blakes hotel in South Kensington, Mario Testino instinctively slips his hand over my Dictaphone, which is on the table between us. He leans forward and whispers, "Please, some chips." The waiter nods, smiles and turns on his heel. Mario Testino is a man of discretion - even it seems when it comes to ordering chips.

For the past 22 years Testino has been creating some of fashion's sexiest and chicest images. His work ranges from straight fashion shoots to celebrity portraiture and appears in magazines from The Face (Testino, with stylist Carine Roitfeld, recently tuned the Wonderbra model Eva Herzigova into a mad cleaver-wielding psycho) to Vogue. He was responsible for the louche, sexy advertising which reinvented Gucci's image in 1996 and also for the now famous shoot with Diana, Princess of Wales for Vanity Fair, showing her relaxed and happy again after years of emotional turmoil. "There were two things that made those photographs. One, that I was lucky to have been asked to photograph her at that moment in her life," he says simply, "and two, I was lucky that we hit it off."

Testino's upbeat, sexy aesthetic has made him one of the most sought-after photographers in fashion. And in an industry which favours youth, Testino's 48 years (as he keeps reminding me) make him all the more extraordinary.

But over the past decade, Testino has also been working outside of fashion. Armed with a small automatic camera, he has been snapping a rawer side of life. These pictures have now been collected in his first book, Any Objections? And the contents are not what you might expect. Any Objections? is a collection of very bawdy snaps. A picture of Naomi Campbell cheekily showing her bum at a party appears, along with a close-up of a man's chest creased with sheet marks; then there's a line-up of men with their pants down printed next to a picture of Kate Moss and Naomi peeing. "I love it when you put images together and they communicate something else," says Testino of the layout of the book.

Pointing out to him that there are quite a few shots of crotches and erections, Testino pauses, holding a crisp in mid-air. "There is only one erection," he says turning the pages of his book until he finds a shot of a naked man and woman side by side. Entitled Adam and Eve and taken in New York, it looks like the morning after a great party. Testino declines to go into details but explains: "I came to the conclusion that the only problem ... the only problem with erections is that they are seen as sordid or negative because they are usually seen in a porn context. But what is wrong with a man having an erection? But, you know, some of these pictures are like me working out my own inhibitions of what I can put in a picture."

Testino says that he started taking these pictures to loosen up his fashion work, which he considered too static. But the compulsion to go out and document what was happening around him soon became a project in itself. "I am really exposed to a lot of life in many different countries and I believe that as a photographer it is your responsibility to capture your time."

The need to document is also the explanation Testino gave to his mother when warning her of the book's subject-matter. "We have reached a time in the world when everything is so open, there is nothing shocking. But when I was growing up, sex was never talked about in public."

Mario Testino followed a circuitous route into the world of fashion. Born in Peru, a background which he says put the love of life and sexiness in his DNA, he started his career studying economics, then law, at the University of Lima. Enchanted by neither, Testino left the country in search of excitement. He found it in London in the late Seventies. And it was here that he also fell in love with fashion and photography. "I like people, I love beauty so it seemed to make sense - and I have always liked clothes," says Testino.

He worked, and still works, punishingly hard. "I remember going to see my bank manager for a loan of pounds 300. He had other photographers who were not getting any work. I really had to tell him that I was going to make it and I convinced him. There were other photographers maybe more talented," he explains, "but I was more hungry. Coming from Peru, I did feel like a third-class citizen, and that meant I really had to prove myself.

"I said to my mother, when you see my name in Vogue, I will have arrived. My first published photo was one which I had taken for a hair salon; they liked it and forwarded it to Vogue. It was printed small but with my name." His first big break came with a cover and shoot for the magazine Over 21, and from there, working with pioneering fashion editors including Lucinda Chambers (now fashion director of British Vogue), Sarajane Hoare (Harper's Bazaar and Frank), Testino forged ahead. "It really is the fashion editors that make the photographer," he says. His closest creative partnership, established in the early Nineties through French magazine Glamour, is with the Parisian stylist Carine Roitfeld.

In a business which has moved from images of high glamour to dirty realism, to sexlessness and the just plain perverse, Testino has a distinctive "lightness", something which he has worked hard to maintain. "It took some time to come to terms with that and a lot of people said, 'You will never make it.' But at the end of the day, I am what am. I love life. As long as the people who are in the capacity of giving me work like what I do, that is all that matters."

So who is going to buy his book? "People in fashion I hope, and young people. I tried to make it not so expensive. I just want to make people laugh. That is my biggest pleasure in life." Any objections?

Any Objections? (Phaidon, pounds 25) is published 24 September