"Dogs have owners, but cats have staff": so goes the saying quoted on a million cat-lovers' coffee mugs, anyway.



Bob, a large and determined marmalade moggy, seems to have appointed James Bowen his butler, chauffeur and nurse at first sight, despite his chosen human's unpromising CV; Bowen had spent 10 years on the street as a heroin addict, was on a last-chance methadone program and had just been allowed to move into a flat in sheltered housing.



He made a bare living by busking, belting out Nirvana songs in London's Covent Garden tourist precinct. As meal tickets go, James Bowen was a poor prospect.

Nevertheless, when Bob climbed through his window, it was clear he intended to stay. He had an abscess on his leg, probably the result of a fight; Bowen had £30 in his pocket, which immediately went on veterinary antibiotics. It was busking money, so he figured he could always make more. It didn't mean he wanted a cat.

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DYLAN MARTINEZ/REUTERS Bob the cat poses with his owner James Bowen as they arrive for the world premiere of A Street Cat Named Bob in London last November.

So he asked around the neighbourhood, trying to find Bob's legitimate owner; having established that he didn't have one, he decided he must be a street cat who should be living wild.

"I tried to send him on his way," Bowen says. "But every day he'd follow me a little bit more. I'd get home from busking and there he would be on my doorstep so he would stay the night. And then one day he actually followed me on to the bus."

Bob, who now has his own bus pass, had decided to become his busking companion. While Bowen played guitar for pennies, he sat on his shoulders, unfazed by the crowds or the snapping cameras that would soon turn him into an internet star.

LUKE MACGREGOR/REUTERS Street musician James Bowen busks with cat Bob in Covent Garden in London.

"It was at that point I felt 'well I am going to have to start taking responsibility for this little creature if he's going to be following me around'. It's not like you can really tell a cat what to do. They do what they want to do."

What Bowen had to do, in turn, was take responsibility for himself so that he could take care of Bob. Ultimately, that meant going through the torment of withdrawal from methadone to become drug-free. The cat, he said later, gave him "the determination to knuckle down and get over it. Using drugs is a selfish thing; Bob gave me something else to focus on".

Since their first encounter, Bob has become the focus not only of Bowen's recovery, but of a series of best-selling books and, most recently, a feature film adaptation. Back in 2011, a literary agent who had been walking past Bowen's busking pitch encouraged Bowen to tell his story with the help of a ghost-writer called Gary Jenkins; A Street Cat Named Bob became a best-seller.

Reuters Even the presence of Catherine, Duchess of Cambridge didn't faze Bob the cat at the world premiere of A Street Cat Named Bob.

Bowen and Jenkins have now co-written eight stories of Bob's adventures.

"There have been worldwide sales in the number of six million for our books," says Bowen. "It's crazy. I mean, it just shows there is a lot of love in the world. And all these people have been brought together just by reading my books, you know, people from different countries who talk to each other now because of their shared love of my books and who go out and raise money for homeless charities. It's amazing."

Bowen, now 37, looks slightly awkward in the hipster Soho Hotel, where he is helping to promote the film version of A Street Cat Named Bob, directed by Roger Spottiswoode. He would probably look slightly awkward anywhere. Bob, who stars as himself in the film, is sleeping off his last interview. This is one of the plushest places in town. You only have to walk a few metres from the hotel lobby, however, to find yourself in the network of alleys where Bowen used to doss.

ITN Bob the cat, star of new film A Street Cat Named Bob, dreams of world domination, according to co-stars Luke Treadaway and Ruta Gedmintas.

During the preparation for the film, he showed the actor Luke Treadaway – who plays Bowen – something of his former way of life. How to beg, for example. Where to sleep. He even showed him how his body reacted to withdrawal.

"There is no way you can explain the physicality of it; you can only see the images of it. It was quite harrowing to watch the final cut of the film, you know. It made me think 'yeah, I'm never going there again'."

Bowen first dabbled with heroin in Melbourne. His mother moved back and forth between Australia and Britain twice; he lived in Western Australia from the time he was three. They moved often, returning to Britain when he was 11 and back to Australia three years later. Meanwhile, young James was diagnosed with several mental illnesses, dropped out of school at 15 and headed to Melbourne.

Supplied Luke Tredaway plays James Bowen in A Street Cat Named Bob.

"My godparents lived in Hawthorn so that was good. But then at 18 I came back to England and everything fell apart. I was a long-haired goth with piercings and all that, because that's what it was all about in the late '90s in Melbourne – and there was a terrible heroin problem in Melbourne at that time too, wasn't there? Then I went on the streets in London and ended up being an addict."

Treadaway, who won a coveted Olivier award for his portrayal of another lonely youth in the stage hit The Curious Incident of the Dog in the Nighttime, prepared by spending one night on a sheet of cardboard in one of Bowen's old sleeping spots over a hot air vent.

"I will never pretend to know what it's like to be homeless, but to get a little taster of it, to know what it felt like to be damp and cold in the morning and to try and pack your stuff up in a bag and keep moving," he says. "The hard thing wasn't actually being there, because I knew I could go home at the end of it. The hard thing was knowing that other people can't. It felt weird doing it when I don't have to: do you know what I mean? But the bigger picture was trying to make it as authentic as possible."

ITN How amazing is Bob the cat?! He sat on his owner, James' shoulders the whole way through the Royal Premiere of his new film, A Street Cat Named Bob.

He also spent time in addiction centres talking to patients, doctors and nurses, which gave him a keen appreciation for what Bowen had achieved.

"I would say that one of the hardest things in the world is to overcome an addiction," he says. "To me, anyone who has overcome that, especially without having the support network some people might, is remarkable really.

"It doesn't mean that anyone who has a cat is suddenly going to save themselves. It's about finding that strength within yourself. It's almost got a fable element to it, this story, because James sowed the seeds for his future by spending his last £30 on getting Bob healthy again. And in that moment, he turned his fate around."

Supplied Directed by Roger Spottiswoode, A Street Cat Named Bob has had solid, if unspectacular reviews since it debuted in the UK in November.

Bowen has now moved out of the flat where he was first given a roof and bought his own house in outer London. Almost inevitably, there has been a tabloid backlash against his Dick Whittington story of recovery – one story accusing him of collecting benefits even as his book topped the best-seller lists, another in which his mother in Australia declared that he had rejected her – but he regards them with the stoicism of someone who has seen much worse.

"That was a ridiculous story, so it didn't matter really," he says of the housing fraud accusation. "What I did, in fact, was put the paper in the cat litter tray."

As usual, Bob got to have the last word.

A Street Cat Named Bob (PG) opens in New Zealand cinemas on March 9.