I was Prince Harry’s ghostwriter. Here’s the truth about what I wrote, why his contribution was ‘hardly illuminating’ and exactly how much he had to do with it…

When shoppers see all those celebrity autobiographies piled up for sale how many of us realise that most have not been written by the famous name on the cover?

More sophisticated readers may suspect that these famous actors, pop stars, chefs, soldiers and athletes have help from a ghostwriter, but do they have any idea how much? Or how difficult that relationship can sometimes be?

I’ve been a ghost for 30 years, working with everyone from explorer Bruce Parry to Strictly stars, and I’m always amazed how little Joe Public know about this dark secret of the publishing industry.

Ideally, the ghost sits down with the celebrity and gets them to tell their story in a series of taped interviews that may take days or weeks. They then go away and work that up into a full-length book, calling the celeb back for clarification and further detail.

But it’s not always that straightforward.

With Robbie Williams, for example, whose first book, Somebody Someday, I worked on (ie. wrote), I went on tour round Europe with him so that he would have the time and space to share his thoughts. Unfortunately, though he was unfailingly friendly and polite, that moment didn’t come too often.

As we had been given an advance of £800,000 to produce the book to a tight deadline, I started to panic. I hassled his management and followed him around post-tour like a mad stalker, even jumping on a private jet trip to Paris.

Mark says he didn’t get to meet Harry when he ghost wrote for the prince on the bestselling book Walking With The Wounded in 2011

Instead, Mark was sent a video of Harry as he enthused about the landscape and his companions but says it was ‘hardly illuminating’

Finally, one evening a week before the deadline, he cracked and told me all I needed to know. When it came out, it went straight to No 1 and stayed in the top ten for 14 weeks, so the angst was worth it.

I did expect him to read it though, given he was doing a publicity tour to promote it. How wrong I was. When a newspaper asked him about his book, he replied, ‘I haven’t read it. It’s full of words.’

Sometimes you don’t even get that close. When I ghost-wrote for Prince Harry on the bestselling book Walking With The Wounded, about four wounded soldiers who trekked across the ice to the North Pole, I didn’t meet him.

There was talk of me flying to Tromsǿ in Norway, to sit down with him for an hour or so while he was en route to join the soldiers who made that extraordinary trip to the North Pole in 2011.

In the end I was sent a video of him out on the ice, enthusing about the beauty of the landscape and the bravery of his companions. For 15 minutes, Harry trekked across the ice grinning a lot in full polar kit. It was recorded just for me but hardly illuminating. The word ‘amazing’ featured a lot, I remember.

This was worked up into a thoughtful chapter, which then had to get copy approval from Clarence House. Whether Harry read it himself, I have no idea.

J.R. Moehringer, who said he was ‘exasperated’ ghost-writing Harry’s memoir Spare, clearly had a tougher challenge and a longer struggle.

If you do end up sitting down with your ‘subject’ (as we ghosts call our celebrity clients), they can be engaging and delightful, especially when they’re talking about themselves.

Once the tape is off, though, you may have to brace yourself for all kinds of bad behaviour, from them immediately ignoring you and catching up on their emails, phoning their celebrity chums or collecting the phone numbers of the beautiful people who approach them in cafes.

Many of these remarkable people are blessed with larger egos than most. Sometimes they will sign up to do a book without understanding that they must include the bad as well as the good.

Ghostwriter Mark McCrum has been in the industry for 30 years

A memoir that is just a compilation of the anecdotes that amuse friends and hangers on will be a tedious read. But when the ghost, in search of the challenges and failures that led to eventual triumph, digs too deep, it’s not unheard of for the relationship to break down completely. Sean Connery twice went back on £1 million-plus book deals once he realised exactly what writing his autobiography would entail.

When the book is finished, which can take between three months and over a year, the ghost’s job is over. Neither the publisher nor the celebrity will want you at the launch party to avoid the danger of letting slip that you wrote it. The same is true of media interviews and promotional events. More than once I’ve chuckled listening to a famous actor on a chat show talking about ‘the struggle’ they had writing ‘their book’, when I’ve known the ghost who did it.

Another ghost whose memoir of a famous pop star won a prize had her hand slapped away by the celebrity she’d written about so brilliantly when she tried to touch the award at the ceremony.

Ghosting has now spread from autobiographies to novels and children’s books. If a memoir is a success, the obvious next step for publishers, after the inevitable sequel or two, is a novel.

Sometimes celebrities skip the memoir. A household name from Strictly I interviewed on stage about his series of historical novels was so put out by my questions about his plots and characters that he jumped to his feet and started dancing, much to the delight of the audience.

Now all this is fair enough, you may say. Nobody is forced to ghost write. As my agent once put it to me, ‘The clue’s in the name, Mark. You’re supposed to be invisible.’

But it seems an ongoing injustice that ghosts aren’t recognised for the skill and experience that makes these stories work on the page.

A friend, who ghost-wrote the brilliant and bestselling memoir of a famous human rights campaigner, died a few years ago, in her fifties. Her obituary acknowledged her other work but never mentioned what to me was her greatest achievement. And as Teena Lyons of The Ghostwriters Agency points out, ‘If a ghostwriter remains nameless and faceless, it’s much harder to negotiate for better pay and conditions.’

I am lucky to have worked at a time when ghosts were well rewarded and often got royalties included. Now, though, ghosts can be asked to do a book for a flat fee of £5,000, which for all the work involved is well below the minimum wage.

The word ‘amazing’ featured a lot in the video and for 15 minutes, Harry trekked across the ice grinning a lot in full polar kit

Mark said he had to follow around singer Robbie Williams on tour in order to get content for the Somebody Someday memoir – with not much luck as the star was so busy

This month, the Society of Authors has launched a campaign calling on publishers and celebs to acknowledge the writers behind these books, including the many written invisibly for children.

Some already do. Chris Hoy appears alongside his ghostwriter at publicity events, while Irish rugby player Johnny Sexton brought his ghost on stage when he won Sports Book of the Year.

But many don’t, preferring to keep things simple and take the credit for themselves.

In the US, these collaborations are more openly recognised, with ghost bylines on the inside front pages, sometimes even on the book cover.

Last January, the American Society of Journalists and Authors launched a Gathering of The Ghosts in New York, including a new award for ghosts – the Andies (named after the ‘and’ of a joint credit).

To me, such openness is a win-win situation. If ghosts got recognition, the reading public could start to judge who’s good, which memoir they should pay to read. Celebrities would have a clearer idea of who to employ. Better ghosts could rise up the ranks and be properly rewarded.

And the ordinary reader wouldn’t go round imagining that writing a book is easy. Or worse, that celebrities are somehow superhumans whose all-round brilliance puts the rest of us to shame.

Mark McCrum latest whodunnit is Murder on Tour (£10.99, Bloodhound Books) is out now