How a 'publicity stunt' on a beach involving King Charles and an ...

It was one of the most iconic photos of the 1970s: the heir to the British throne striding out of the sparkling surf at Cottesloe Beach in Western Australia, only to be accosted by a young woman who planted a kiss on his cheek.

Charles, then the Prince of Wales, was on a tour of Western Australia to mark 150 years since European colonisation.

He was also, much to the growing concern of the royal family, 30 years old and still single.

His parents wanted him to settle down, get married and produce an heir, which was difficult when they had already denied him his first choice of bride in Camilla.

Charles was "very happy with the way he lived his life," according to biographer Jonathan Dimbleby, "and would have remained a bachelor if not for the need to produce an heir to the throne."

But the choice was not his alone to make and the British tabloid press was growing restless.

"Ever since Charles was around the age of 18 the press had been looking at every girlfriend and asking, 'could this be our next queen?'" Charles biographer Penny Junor said.

"They delved into the background of all of these women, which put an awful lot of them off."

As speculation grew to a fever pitch, the image of Charles wearing remarkably short shorts while in the arms of a young model quickly appeared on front pages of newspapers worldwide.

The prince, who risked being branded an old maid in the tabloids, was suddenly cast as the world's most eligible bachelor, a modern royal whose frolic in the surf with a beach babe stood in stark contrast with his more stately, traditional parents.

But the seemingly spontaneous moment in the waves was not all it seemed.

In the decades since, conflicting accounts from people who were there that day have suggested the photo may have been staged.

This is how the stunt unfolded, according to the model asked to run up to the prince, the photographer who snapped the shot, and the future king at the centre of the plan.

Jane Priest was a single mother in her mid-20s when she first encountered the Prince of Wales on his tour of Perth in 1979.

The model was relatively unknown until photos of her planting a kiss on the royal's cheek made front pages all over the world.

Prince Charles was enjoying a quick dip at Cottesloe Beach in Perth when he was snapped by photographers. (Getty: Kent Gavin/Mirrorpix)

But long after the famous image went to print, the Australian woman revealed her public smooch wasn't a spur of the moment decision at all.

The 'publicity stunt', she said in an interview with UK newspaper The Standard, was orchestrated to make Charles look more approachable.

The 'set up' had been arranged the night before when Priest was brought in for a meeting to make sure she was the right person for the job.

The next day, as her son sat building sandcastles nearby, the model made her way down the beach and into the path of the prince.

It didn't all go according to plan.

"When he saw me, he dived into the water, so I thought I'd follow him in, but as I went in, he got out," Priest told the newspaper.

"So I followed him out, hair ruined, make-up ruined, and I felt like such an idiot. I actually went and put my hands on his chest to give him a kiss and Charles said: 'No, I can't touch you, I can't touch you.'"

Awkward as the moment may have been, the 'stunt' worked, transforming the public persona of the prince from reserved to modern and carefree.

But Priest's account of what happened has been disputed by others who were present that day on the beach.

Photographer Kerry Edwards claims he was the man who took the photo that made global headlines.

According to his recollection, he had been camped out at Cottesloe that week, preparing to snap pictures of Prince Charles on his usual morning run and dip in the surf.

Kerry Edwards said he was the photographer responsible for setting up a shot of a model kissing Prince Charles. (ABC News: Briana Shepherd)

While not known to be a sportsman as a kid, Charles has reportedly maintained a fitness regime for most of his life and been compared to a mountain goat by his wife Camilla because of his fondness for walking.

The young royal's quick dip in the surf in 1979, however, ended very differently to his usual routine.

In Edwards' account of the kiss in the waves, the photo op was his doing and not the work of the Prince of Wales's press team.

"The media and the international media gathered here every morning to record the event," he told the ABC in an interview in 2015.

Edwards recalled that it was his desire for more glamour on the front page of the Sunday papers that ultimately prompted a search for someone to flirt with the prince.

"I was actively involved with the social writer for the Sunday Independent and a couple of phone calls later we found a willing person to come along and have a swim with Charles," he said.

"I think it was good for Cottesloe, probably good for Jane Priest. [It] certainly put Cottesloe on the map, didn't it."

He's not the only person to take credit for sending Priest over to the Prince of Wales.

Royal photographer Kent Gavin has also claimed he was the mastermind behind the shot.

"I had the idea, I said: 'wouldn't it be great if we could get a lovely young model?" he said in the Amazon Prime documentary 'Royalty Close Up: The Photography of Kent Gavin' in 2013.

"So I said to Jane: 'Look, when he comes out of the water, run up and kiss him.'

"So she's over there, she's standing, and I said: 'Right, go now'. And he knows he's been set up because his royal protection officer shouts: 'It's a set-up sir, it's a set-up!'"

Despite the divergent accounts of what occurred on the beach, its legacy lives on to this day.

The photo of Charles on Cottesloe beach remains one of the defining images of his very long tenure as heir to the British throne.

King Charles riding a horse at a station in the Murchison region. (Supplied)

Twenty-five years after he strode out of the waves that day in 1979, he returned to Perth a very different man.

While he was still waiting to accede to the throne, he was a father to two sons, and finally engaged to the love of his life, Camilla.

During the visit, he was asked about his fondest memories of his time in Perth.

"These memories are of enormous importance to me, and also all the memories of all the kindness you've shown me, and the fun I've had in this part of the world," he said.

"Recollections of swimming very early in the morning down the beach, when one or two people were detailed off to run up from the surf and do unmentionable things to me."

Priest has also maintained her sense of humour about her very brief brush with royalty.

"This was a five-minutes-of-fame thing. I was never going to be Queen Jane, let me tell you," she said in 2012.

"Apart from anything else my background wasn't clean enough."