His Cherub spy books for teens have sold in their millions but are banned in some schools because of their graphic content. Robert Muchamore argues that his subject matter is no worse than what you'd see on EastEnders, as his latest Cherub novel, Guardian Angel, is published.

By Hannah Stephenson

Robert Muchamore has gone from schoolboy geek to publisher's dream, his action-packed Cherub series of spy adventures selling in their millions.

His stories, featuring agent James Adams who is a member of Cherub - a secret branch of British intelligence which uses orphaned 10 to 17-year-olds as agents - are loved by kids but not always by their parents.

The books are grittier and less glamorous than those of fellow young adult author Anthony Horowitz, creator of the Alex Rider spy series, less horror-filled than those of Charlie Higson, but feature plenty of swearing (although not sexual references), teenage sexuality and subjects like drug-dealing and human trafficking.

It's this kind of subject matter which has led Muchamore into controversy - his books have been banned in some schools - but he remains unapologetic for ruffling feathers.

"They do get banned occasionally," he says happily.

"I had this fabulous quote from a boy in Year 6 who said, 'Your books have taken off like wildfire since they got banned from my school'. I thought that summed it up perfectly."

Muchamore, who aims his novels at 11-year-olds and upwards, does have a rule of thumb for content.

"Broadly speaking, anything that happens in one of my books could be shown in an episode of EastEnders," he explains.

"That kind of pre-watershed TV show would be about the level that I would set the content in a Cherub book."

He wrote the first Cherub series of 12 books in chronological order, the hero ageing with each nail-biting episode, but had to stop when James was 18 and too old to be in Cherub. So he's written a second series featuring 12-year-old Ryan Sharma, a promising new Cherub agent.

In his latest novel, Guardian Angel (the second in the new series), Ryan is tasked with destroying a billion-dollar criminal network run by the family of one of his friends.

Muchamore admits he's had to tone down the language a bit over the years, revealing that his editor ended up counting the number of swear words in each book, until they compromised on an acceptable level.

"Sometimes I still get marshalled, if I go a bit over the top," he grins.

His heroes, first James and now Ryan, are based on who he wanted to be.

"Everything about James is me, except for the fact that he's a good-looking, tough, cool guy who always gets the girls. He hates mayonnaise because I do, he supports Arsenal because I do. He is me, but he's a lot cooler."

Muchamore used to work as a private investigator, which sounds rather exciting until he starts talking about it.

"It was mostly hunting missing heirs and beneficiaries. We also used to do research for newspapers, but post Leveson inquiry it's probably best not to mention that.

"I never got into any sticky situations, it wasn't that kind of job. I just used to work in an office and phone people up and occasionally go and speak to them. We weren't chasing people for missing stone falcons or missing people."

He's recently come in for flak by arguing that 'cosy' authors, like Julia Donaldson and Michael Morpurgo, shouldn't be the sole representation of children's books.

"It just gets on my nerves a bit because when children's authors are represented on television, they often dig up the same names. It's often a bald, grey-haired man or an elderly woman and they all tend to be quite cosy and safe kind of people.

"It's not that I've got anything against those people as individuals, it's just that there is a younger generation of children's authors. If you want to get 13-year-olds reading, you want someone a bit younger who's writing a different kind of book."

The son of a milkman, Muchamore grew up in a working class family in north London and wanted to be a writer from his teenage years.

"I kept trying to write literary novels, I fancied myself as a Booker prize-winner, but that didn't pan out."

He was, by his own admission, always a geeky kid. He wasn't bullied but wasn't part of the in-crowd either.

Then on a trip to Australia to visit his sister, Muchamore's 12-year-old nephew said he had nothing to read, which sowed the seed of an idea to write books for young adults.

"It's that awkward age when kids are a bit beyond Harry Potter but they still want to read about people their own age. I wanted to do something set in the real world that was believable but interesting, maybe tying into my work as a private investigator."

He wrote The Recruit, the first in the Cherub series, in 2001 which was initially met with a pile of rejections but was finally published in 2004.

It was a slow burn to success, but as word of mouth got round, the book - and the series - took off and by 2005 Muchamore was earning enough to be able to quit his private eye job.

"It's one of the things I'm quite proud of. There wasn't some enormous marketing campaign. It was word of mouth from kids, parents and librarians, then The Recruit won the Red House award (the only national book award voted for entirely by children) which helped to push it. That built a sustainable model for success."

To date, the Cherub series has sold more than five million copies and been translated in more than 20 languages. The film rights have been sold and Muchamore receives 35,000 hits a day on his Cherub website and answers all the fans' emails himself.

Kids seem to be most interested in what kind of car he drives, he muses.

"They always think I'm driving around in an Aston Martin or a Ferrari, but I'm a really bad driver and I don't own a car."

He also writes The Henderson's Boys series, a prequel to Cherub, is working on a screenplay, and has found time to deliver three more books to the publishers, ahead of his tour of Ireland this autumn.

He breaks the mould of writers who have come from highly educated, privileged backgrounds. Indeed, Muchamore left school with one A-level (a D in politics) and never went to university.

"Writers do tend to be quite posh and middle class, don't they? Their parents are usually university professors or journalists."

Muchamore turned 40 this year, is currently single and doesn't have any children of his own. "I can't bear them," he jokes.

So how does he tap into their mindset?

"Having kids is possibly the worst thing you can do if you want to be a kids' writer because when you become a parent you become a protector. You don't see life from the kids' perspective any more."

He bought his dream house, a five-bedroom bachelor pad in an upmarket area of north London, two years ago, where he lives on his own. But turning 40 has made him think about finding a partner.

"Now I've hit 40, I'd quite like to meet someone and have a family and do all that kind of stuff. For the last 10 years I've been focused on the writing. Now I need a wife and five kids to fill up all those bedrooms.

"You can put that in your article with my email address..."

:: Guardian Angel by Robert Muchamore is published by Hodder, priced £12.99. Available August 2