Interview: Ricky Gervais, Comedian and Filmmaker

Pilkington's awkward detachment from the world and his bizarre observations and opinions about things such as the internet ("The web is the new book, though, innit?") and nature ("If an animal is named after what it eats, how interesting is it?") often had the pair in stitches.

Pilkington featured increasingly more on the show and the three then decided to record some podcasts together.

The popularity of these podcasts spread like wildfire across the internet, making them the most downloaded of all time, and audiobooks from the series were also snapped up. A cult grew around Pilkington although he was so indifferent to the whole thing that some people started to think he was the scripted creation of Gervais and Merchant.

While they fervently deny this claim ("If Karl isn't really like that, he keeps the act up 24/7," is Gervais's take on the matter), the line between reality and fiction is further blurred in a forthcoming TV version of The Ricky Gervais Show podcasts, which comes in the form of an animation.

The three men are certainly ripe for caricature. Merchant's thick specs and long limbs make him look a bit like a cartoon in the flesh anyway, Pilkington's spherical head actually gave rise to one of the podcasts' most oft-quoted phrases ("head like a f***ing orange"), while Gervais, who has lost nearly a stone in recent months and is looking tanned and relaxed following a stint in the US, takes on his former, more rotund outline.

"In real life I look like Brad Pitt but in the cartoon I thought it would be good if I looked fat and unattractive," Gervais says, faithful to the self-deprecating humour which made him famous.

"I look like Fred Flintstone, Stephen possibly like Barney Rubble and Karl is like Charlie Brown."

The show combines the conversations between the three, exactly as they were on the podcasts, with animations of them sitting in the studio. When Pilkington trails off into an anecdote or a far-fetched argument about monkeys in space or what he would do if he was on I'm A Celebrity... Get Me Out Of Here!, the animation follows.

"We wanted the cartoons to be retro and cuddly and not too spiky and trendy because the things we talk about are pretty much out there," says Gervais.

"There are no taboos. We were doing it for the internet, so we felt we could do what we wanted, and we wanted the animations to show that we were safe because Karl's a cuddly little creature really.

"He's like a child, he's an idiot savant. He thought that Anne Frank was just avoiding paying rent, but there's no malice."

It's no surprise that he admits he "can't get enough of" Pilkington and that despite his huge success as creator and star of The Office and Extras, and his leading roles in films Ghost Town and The Invention Of Lying, his favourite work is with the child-like Pilkington.

Gervais explains: "I don't really have a better time career-wise or work-wise than sitting in a room with Karl and, honestly, when I wake up the first call I make is to Karl. He is like the reaction shot to my life. It's not enough for me to experience the world, I have to know what Karl thinks."

Having received rave reviews in the US, where the show was first aired, and likely to be a hit at home too, Pilkington now faces the prospect of fame outside the circle of the podcast enthusiasts.

"Karl has a sister and they hadn't seen each other for about 15 years and they bumped into each other in a car park in Manchester and he said, 'How's it going?' and she said, 'I've had another kid' and he went, 'Oh all right' and she went, 'Do you want to see a picture?' and he went, 'Not really, it'll look the same as the last one'. Sometimes I forget he's a real person," Gervais says.

The Ricky Gervais Show, Channel 4, 10.30pm