Jerry Hall's latest prey

For a man more used to pursuing exotic species in far-flung rainforests, it must have come as something of a surprise for Benedict Allen to suddenly find himself as the prey.

The setting was a private dinner party in London six weeks ago. Allen - the mettlesome TV explorer and author, known as much for his good looks as his intrepid endeavours - had been put next to none other than Jerry Hall, an undoubtedly exotic specimen in her own right.

According to a close friend of Jerry's who observed what came next at the dinner party, it was a case of Allen finding himself rather like a deer in front of blinding headlights. "It was classic Jerry," he told me yesterday. "If she is attracted to a man, she makes him feel he is the absolute centre of her world. She's absolutely brilliant at it. That Southern charm is like a fullon beam that just blinds them."

It certainly seems to have worked with Allen. After this first proper meeting, the explorer and the model did not swap numbers, I am told, but eventually got in touch through a mutual friend. On Monday night, they were very much together - in front of 200 photographers, 3,000 fans and Prince Charles - at the royal premiere of Russell Crowe's new film, Master and Commander.

Afterwards, they joined former Rolling Stone Bill Wyman for dinner at The Ivy. They left the restaurant together, although Allen tried his best to avoid lurking paparazzi.

Allen, 43, a former public schoolboy, has not yet been a guest at Hall's £5 million home in Richmond, which she once shared with Mick Jagger, former husband and father of her four children.

Contrary to some press reports, Jagger no longer lives there - he once had an annexe with a connecting door to the main house - but Hall, 47, is discreet in her relationships and protective of her children. "She does not take her boyfriends home until she is sure they are serious and so on," her friend went on.

Her friends also concede that when it comes to Jerry and men, there remains one overriding influence, and that is Jagger himself. He remains such a pivotal figure in her life that Allen, they say, should tread carefully.

"Mick looms very large as far as Jerry is concerned. He is the father of her children. What you have to understand about Jerry is that after the initial burst of excitement, after, say, three or four months, Mick comes into the picture because of the children, and that can be very daunting.

"I've seen it happen where some of her men just find it all a bit too difficult to cope with. She's loyal to them, and she doesn't want to be with Mick, perhaps, but they are bound together and always will be. You have to be a pretty strong man to put up with that, let me tell you."

Perhaps Allen, the son of a test pilot whose own mother died on Christmas Day nine years ago, is precisely that. He is, after all, the man who as a 23-year-old gap year student, fought his way through the jungles of South America, famously being forced to eat his mongrel to survive; who endured painful tribal initiation rights in New Guinea; and who, by his own admission, prefers the rigours and sacrifices of exploring to settling down in London. The menu at The Ivy would be a rare - and not always welcome - indulgence.

He is, if you like, something of a social playboy crossed with Indiana Jones, although not one without his detractors. Allen accepts that some have greeted his tales with a certain scepticism and he has had to defend himself against allegations that he exaggerated parts, including in one instance other explorers arguing that he could not have travelled 1,000 miles through the Brazilian jungle in such an astonishingly short time.

Nonetheless, his friends defend him. "He's a man's man," one said yesterday, "who falls easily for women. But he's no pushover."

It's a resilience - both physical and emotional - which he has shown since his schooldays, a tenacity which he will need as Jerry Hall's latest trophy. Nigel Suffield-Jones, who taught Allen at Bradfield College in Berkshire, recalls the back-breaking - they were once referred to as "character building" - military exercises that Allen threw himself into as a 16-year-old schoolboy.

"They had to walk for 25 miles in the worst conditions in November, across some of the highest peaks of the Brecon Beacons," he said at his Berkshire home yesterday. "The idea was to stretch them beyond the limits they thought they had. We would make them march up to the highest parts, to Pen-y-Fan and so on, to stretch them."

What remains fascinating about Allen, however, is that he - in terms of girlfriends and even friends - is something of a loner. "He was never memorable at school," a former fellow pupil, Andrew Tenison, said yesterday. "He just never stood out in any way."

Certainly, he has had very few girlfriends: one of the longest standing was Jita, a beautiful fellow explorer, who once described him as "nuts". Another was a 17-year-old tribal girl called Kwavarane to whom, he says, he became "very close" but remained just friends, not lovers.

Allen himself - and Jerry Hall take note - says that he has found it difficult to sustain relationships because of his commitment to exploration. "Travel has put a big strain on my relationships," he admitted. "The next expedition is always looming. Do I tell a woman to hang on in there when I'm going to be in Mongolia for eight months with no possible way of communicating?"

His inability to sustain a permanent relationship still rankles with Allen - but it may not be such a big deal with Hall herself. In fact, say her friends, Allen's very casualness is part of his appeal to her. "I've seen it happen so much with Jerry," her friend told me yesterday.

"When she tires of a man, it's just like a light switches off. She just drops them suddenly and I know that, for some of her boyfriends, it has been very painful. She doesn't set out to hurt, but that is the inevitable outcome. They feel that maybe they've been dropped. And she is a celebrity, after all." It is something, say friends, which affected her last prominent boyfriend, London businessman Tim Attias, who once proposed to Hall.

Benedict Allen - survivor of rampaging tribes, earthquakes and tropical diseases - has been warned.