'Kong?' says the driver. 'We used to see him all the time but not any more. I'd like to see more of him. Say hello or whatever. We all would.'

He looks put out on the part of a nation. 'I mean, here I am, a kiwi, and here's you from the other side of the world. Do you think it's right that you see him and I don't... Oh, hang on, mate, look up there, it's Skull Island.'

As he points, a timely squall rushes in from the Pacific, sinking the coastal road we're on in darkness. Despite the mood lighting, Skull Island - Kong's fictional home - looks no more than a dusting of suburban trees. If you squint, it also looks suspiciously like Tolkien's Shire. 'And over that hill,' he gestures across the harbour, 'is where the real Kong lives.' The view is blocked by a big ship knocking back and forth on the swell. 'Venture' says the nameplate. Previous Ventures carried misguided directors, scream-queen starlets and a crew of mercenaries from the New World to the Newer World looking for Kong. 1933's version was a cinema classic. 1976's was rather more campy. They're after Kong again this Christmas, but with the latest take on the ape already in the can Venture is being dismantled. It's docked at a concrete jetty, and technicians crawl all over it in the wet, making its rusty hull writhe.

Though signs of him are everywhere, 'the real Kong', aka the film maker Peter Jackson - whom my hotel bellhop describes with sage gravity as 'tricky' - cannot be disturbed this evening. Instead a far-flung room, a bad meal and fitful dreams of that spooky ship give your interviewer something of a Fay Wray moment, which persists into morning as his audience with Kong approaches. Jitters aren't helped by the extent of the subject's local fame. His hairy portraits hang in public spaces and his name can be overheard in any of the capital's bars, where, as with the taxi driver, his clandestinity is often bemoaned. Coming to New Zealand to meet Peter Jackson begins to resemble going to Cuba to meet Castro, or Disney World to meet Mickey Mouse.

For a supposed recluse, Jackson is easily found, however. In a low-rise industrial estate he owns many of the buildings, and today is in the final stages of cutting King Kong at his multi-million-pound post-production facility. The sprawling lobby has the look of an up-market ski lodge and is staffed by beefy locals who - like donkeys at a day spa - look unsure of how to interact with the finery. As with most folks in New Zealand they seem in awe of him. One escorts me across the lobby with an air of crisis. 'He doesn't mind being interviewed,' it is said, but I'm asked to 'bear in mind he has a movie to finish'.

Up an elevator operated by security card, into an antechamber, then the study. Stone-clad fireplace, thickset oak furniture and the 44-year-old Kong stood in a bay window, silhouetted against the New Zealand gloom. It's tough to tell if he's smiling, but the trademark elements are in place. An unruly black beard, set against the kind of bleached pallor that comes from a lifetime spent in the dark. But then there's his size. Absolutely shocking. He's as unexpectedly slight as the Wizard of Oz.
'Hi.' He drinks tea from an earthenware mug and, contrary to legend, is wearing both trousers and shoes, comforts he forgoes when filming.

'Oh my God, you're so thin!'

'Err... thanks. Nice to meet you too.'

'No, seriously, how much weight have you lost?'

'Seventy pounds. Maybe a bit more.' After years of being likened to a Hobbit, Jackson says he has swapped the deadlier sins of the catering truck for muesli and yogurt.

Though he had laser eye surgery and lost his glasses too, the one-time film geek still finds it borderline ridiculous to be asked about his appearance. After all, he's not Renee Zellweger. 'No, I'm not.' We take armchairs by the fire. 'But I'm Kong, am I?' he laughs. But he is, and not just because he spent 30 years trying to make a movie of it, not because he was eventually paid $20m to shoot it a minute's walk from his back door, and not even because it's what some have taken to calling him. It's because in show business, Jackson is a giant of such proportions, he might as well straddle the Los Angeles hillside and gnaw on the H of the Hollywood sign.

When the Lord of the Rings trilogy made its 2.9-billionth dollar and won its 17th Oscar (11 of those at the 2004 ceremony alone), Premiere magazine named this nervy-eyed writer/director/ producer the most powerful man in movies. Sitting in his study today, he seems odd casting for the role. With no cigar, and a soft voice that breaks into a warm, nerdish giggle when he gets excited, he sits forward, arms folded in his lap, not 'owning the room' like Welles or Huston might. The man is normality itself, even if his story is not.