Whitney Houston may have been one of the most acclaimed singers of her generation but when David Roberts was asked to be her bodyguard he wasn’t exactly star-struck.

“I said ‘Whitney Houston, who’s he?’,” recalled the former police sergeant turned close protection officer.

He went on to spend six years protecting the late superstar as she toured the world and believes he was the inspiration for the 1992 film The Bodyguard, starring Houston and Kevin Costner.

“It was an eye-opener, bearing in mind I’m from a farming community on the tip of north Wales, the Llyn Peninsula.

“And here I am travelling the world right with arguably one of the most famous people in the world so it was quite an interesting experience,” said the 72-year-old, speaking from his home in Palm Beach, Florida.

Twenty-five years on he has written a book about his time with the star who died aged 48 in 2012.

David joined the RAF Police in 1968 and served in Northern Ireland before joining North Wales Police in 1972.

He later transferred to the Met Police, concluding his service in 1988 as a sergeant providing protection for visiting dignitaries and heads of state.

It was while working for the American embassy in London in 1988 he first met Houston after she flew into the UK.

He recalled meeting a “most sophisticated, educated, intelligent, shy young lady”.

“I was singularly impressed,” he said.

“Her beauty was outstanding, even after the long flight from New York to London.”

Ahead of the meeting his daughter had brought him up to speed on her career and he had been out and bought some of her music.

“She had the voice of an angel, clearly,” he said.

He and Whitney “got on famously” from the get-go.

The initial job was for three months but he was later asked to be the director of security for her Far East tour.

“I can’t imagine a high-profile personality in so much demand being easier to look after,” he said.

He said she spent most of their time in her hotel room on the phone to her then boyfriend, comedian Eddie Murphy.

“He is just as funny off stage as he is on stage, a great chap, I like him,” said David.

He would later witness her tumultuous relationships with singer Bobby Brown who she married in 1992.

They remained married for 15 years.

“It’s remarkable to me it lasted as long as it did,” said David.

“In fact, the day of the wedding all the people who were involved in the security there said, ‘OK guys, we’ll be back here next year for the divorce party – we really did not think it would last and yet she proved us all wrong.”

As for his own relationship with the megastar, he said he got to know her “to the extent that there was very little need for conversation when we were out in public”.

“I’d look at her and know what she’s thinking and what she wanted or if we were in a crowd or I’d feel a tug on the back of my jacket we had to go.”

“There is always that level of synergy between the protector and the protectee,” he said.

He would check Houston into hotels using the name Rachel Marron – the name of the character Houston would go on to play in The Bodyguard.

But he insisted not everything in the film is as true to life.

In the film Costner and Houston’s characters develop a romance but he insisted he was “more like a “kindly uncle” to the star.

When asked if he would have died for her he is unequivocal.

“Of course,” he said.

“If I did my homework wrong, if I got the threats assessment or the risk management or the preparation wrong, then yes, I would have paid for that, yes.”

And there was plenty of risk to assess.

During the Far East tour he said there were about 50 fans who were considered a potential threat.

“The obsessed fans were not just happy to see her, not just happy to be in her presence, they wanted a piece of her, and that’s when it becomes a little bit tedious from my perspective,” he said.

“We had one that would write reams and reams and reams of all manner of mentally disturbed comments on toilet paper.

“There was a chap in Australia who used to send his soiled underwear and socks.”

He said the man had written he was going to be at her show in Sydney.

“He gave us his seat number and advised that when she sang the encore Greatest Love of All he was going to come on stage and ‘take her to meet his mother in heaven’.”

He was surrounded by undercover officers but the concert finished without issue.

“He didn’t move, he didn’t show one sign of emotion at all,” said David.

“She finished singing, he stood up, he walked out, we’ve never heard from him since.”

This insight into the world of the mega-famous left David questioning why so many young people chase stardom.

“It was patently obvious to me from the very beginning that that level of fame is too expensive a price to pay,” he said.

He said the only time she could achieve any type of normal life was when she was with friends and family or in a hotel room “otherwise, nothing was normal”.

He said years spent following Houston around the world “came at a cost” to him too.

When asked if that cost was to his own personal relationships he said: “You’d have to ask any one of my three wives, I’m not entirely sure.”

The job came to an abrupt end in 1995.

He said for the last nine months they were together he witnessed Houston’s “gradual but obvious deterioration”.

He said he never saw drugs paraphernalia but frequently witnessed the star in emotional distress.

“There was a problem that needed to be addressed by those who cared for her, not just the family and friends, but the executives who were making millions from exploiting her to the extent that they did,” he said.

“But the general consensus at the time was that Houston could not possibly go to rehabilitation as it would be detrimental to her reputation and career.”

He said he raised concerns.

“I was told ‘Miss Houston has decided she’s not going to travel internationally anymore, so she doesn’t need someone of your expertise, but if ever she decides to travel again, we will call you’,” he recalled.

“So that was the end of that.

“That was technically my swan song, that was the bullet that I did take for her.”

In 2012 at just 48 Houston died in her room at the Beverly Hilton Hotel of accidental drowning due to the effects of cocaine use and heart disease.

“It hurt. It was dreadful,” said David.

“You get over the initial shock and then the anger takes over because it shouldn’t have been.”

Then in 2015, Bobbi Kristina Brown, the only daughter of Houston and R&B singer Bobby Brown, was found unresponsive in a bathtub at her home in Georgia and died six months later.

David remembered Houston being wheeled out of the livery room with Bobbi in her arms and as she grew, watching her run around playing games.

“The only solace you get from the entire affair is believing that she [Houston], her father, her mother and her daughter are reconciled in a place that no-one could hurt them anymore,” said David.

He said he had written his book, Whitney: The Memoir of Her Bodyguard, to “dissipate the anger” he has carried ever since Houston’s death.

“The entertainment industry is a beast. It has demands that are unrealistic. You take a young 20-odd year old girl and you make them this famous, there are demands, you’ve got to produce 10 albums in the next five years – but where’s the normal life? You haven’t got time for that,” he said.

“You’re part of our money-making machine and that’s what she was”.