Mackenzie Crook: A star in geek's clothing

He may play a loser in TV's 'The Office', but his ambitions go far beyond the sitcom, he tells Veronica Lee

My interview with Mackenzie Crook gets off to a bad start when he fails to turn up. We reschedule for a week later and an embarrassed Crook greets me with profuse apologies and a disarming, "I completely forgot about it. My agent goes on holiday and my life falls apart."

It would be tempting to think that Crook, 30, is as much a social inadequate as Gareth, the sad-bloke character he plays in BBC2's The Office. But he's just a little fey, that's all, and a few minutes in his company is enough to restore good relations.

We start by talking about The Office, the superlative and award-winning sitcom written by Ricky Gervais and Stephen Merchant that was an overnight hit last year and returns for a second series at the end of the month. Crook plays Territorial Army reject Gareth, who probably is secretly in love with his boss, the ghastly David Brent (Gervais), while everyone else despises them both.

Crook hugely enjoys playing Gareth, and even admits to some empathy with him. "He's all right, but he's a vindictive bastard," Crook says. "I cringe for him because he's a little boy who has found himself in this adult world and is completely out of his depth." Is he anything like Gareth? "I have classically boring hobbies and I am a bit of a sponge for trivial information and stuff like that. There are probably more elements of Gareth in me than I would like to admit."

Crook modestly plays down his character's part in the second series – "Gareth would be happy with the status quo and so it's right that he doesn't develop as much as other characters" – and then lets slip a storyline development that will surely cause many guffaws (as well buttock-clenching moments of embarrassment) this time around. "He becomes a bit of a ladies' man – women I'm sure he meets down Chasers nightclub – and the others wonder if he's making it up. It's excruciating but there are poignant moments as well."

How much of the character is his creation and how much is the writers'? "It sounds like I'm licking Stephen and Ricky's arses, but Gareth is so well written that there's very little I have to do to build the character because it's all there on the page. They are very focused in their writing and know exactly who Gareth is."

Crook grew up in comfortable middle-class Dartford in Kent, an Office hinterland if ever there was one. When he failed to get into art school, he had to think about what he wanted to do. Crook had belonged to a youth theatre and realised he had a talent for performing, so in 1992 he created his comedy character Charlie Cheese, a spot-on recreation of those corny end-of-pier comedians turned TV quiz-show hosts that we all hate. Crook later created Mr Bagshaw, a horribly recognisable PE/Geography teacher dressed in a nylon tracksuit and tie who in turn patronises and humiliates pupils while never realising that he is deeply hated by his charges.

I ask if it's significant that Crook has only ever done stand-up as characters. "I knew that I didn't want to get up there as myself," he replies. "I wouldn't have anything to say as me. I can write comedy, but I'm not the funniest bloke down the pub – I know a lot of people far more witty and spontaneous than I could ever be. My act is very scripted, although I can respond to hecklers in character – I'm not too sure I could as me." But Bagshaw must have got under his skin; Crook is developing the character in a sitcom pilot for the BBC.

At least he can wear a wig for Mr Bagshaw; Crook had to walk around with Gareth's haircut for months during the filming of The Office, and even had it when he got married last year, which upset his mum no end when she realised the wedding pictures would record it for ever. But Crook's distinctive looks have gained him a nice sideline in films, as drug-dealers, ghosts and spooks.

"They get me noticed at auditions and I've done a lot of small parts in big films," he says. I suggest that he might be ideal as an East End gangster in Guy Ritchie's next film, which makes Crook laugh. "That would be brilliant, but I wouldn't know how to go about getting that role, or even whether it's for me to put myself forward." What he would really like, though, is a role in a David Lynch movie. "That would be incredible. I just love his work, it's so dark and cynical. He creates a strange world inhabited by weird characters in a style that is distinctly his." He catches himself sounding pretentious. "I mean, I don't understand a word of it, but it's fascinating."

In the past year or so Crook has worked with Dustin Hoffman, Johnny Depp and Christina Ricci in forthcoming Hollywood films and this week he flies off to the West Indies to work with Depp again; Pirates of the Caribbean will be released in the spring. So is Hollywood the way forward for him? "I'd love it, but I'm not good at the other stuff – the idea of going out of my way to schmooze people just doesn't appeal. But if they want me to be the next Tim Roth, I'm ready."

A new six-part series of 'The Office' starts on BBC2, 30 September, 10pm