_ Royal family will be horrified by Rebel Wilson's claim a member of The Firm invited her to a drug-fuelled orgy after it revives memories of cocaine use by Prince Harry, Lord Frederick Windsor and Camilla's son

Members of the Royal Family will be recoiling today, as Australian actress Rebel Wilson has claimed a person in the Firm invited her to a drug-fuelled orgy at the home of a US tech billionaire in 2014.

In her new book, Rebel Rising, the Pitch Perfect star, 44, says a male member of the royal family who was 'fifteenth or twentieth in line to the British throne' 'floundered around' at the party where drugs were being passed around 'like sweets'.

While she has not named who it is, certain members of the family, and those adjacent to it, have publicly spoken about drug use in the past.

Prince Harry famously wrote he had taken cocaine 'a few times' in his memoir Spare. Meanwhile, both Lord Frederick Windsor and King Charles' stepson Tom Parker Bowles have admitted to cocaine use. There is no suggestion these are the people Rebel is referring to.

Here, Femail looks at the royals who have spoken about drug use... 

TOM PARKER BOWLES 

In 1999 Camilla's son, Tom Parker Bowles, was caught in a sting set up by the now-defunct News of the World.

Tom, who was 24 at the time, was secretly filmed giving  cocaine to a journalist while working at the Cannes Film Festival in France.

Later, he also admitted using cocaine himself with 'someone he found last night' while working in France.

Charles, who was then a patron of the drugs charity Phoenix House, was 'fairly cross', and 'scolded him,' according to reports at the time.

As well writing about drugs in his memoir,  Spare, Prince Harry's drug use and partying lifestyle has been well documented. 

In Spare, the Duke of Sussex sensationally admitted to having taken cocaine 'a few times' during his wilder party years. 

He also confessed to taking cannabis and magic mushrooms, and ended up hallucinating that a bin was talking to him.

He also described smoking cigarettes and cannabis and drinking at the Windsor Castle golf course while he was a student at Eton. 

During the Golden Jubilee in 2002, the Duke described being dragged into an office by an anonymous Royal Household staff member after a reporter enquired about his drug-taking habits. 

In February 2002 it was also reported that King Charles, then the Prince of Wales, sent Harry to visit Featherstone Lodge Rehabilitation Centre in Peckham. 

His Majesty took the decision after finding out the prince had taken drugs at parties.

In 2012, Harry enjoyed a wild weekend in Las Vegas, where he was snapped in just a necklace while a naked girl hid behind him following a game of strip billiards in his VIP suite.

LORD FREDERICK WINDSOR 

Lord Frederick Windsor, the son of Queen Elizabeth's first cousin Prince Michael of Kent, also admitted to taking cocaine after a photo was taken of him on the floor of a London club.

A 20-year-old Freddie admitted to taking cocaine when he was photographed spread-eagled on the floor of a London club after attending a film premiere.

His mother, Princess Michael of Kent, expressed her dismay saying: 'I brought up my children to be anti-drugs and I am disappointed but he has assured me he won't do it again and I trust him.'

She added: 'He's down as a drug user, but he's not. You just have to watch him in action. Freddie is not a junkie.'

Freddie responded that: 'It's very difficult to avoid getting into this sort of thing when you move in these circles.'

To teach him a final lesson, Lord Freddie and his younger sister Lady Gabriella Windsor were taken by their mother to a drug rehabilitation centre so they could see the problems caused by addiction.

It was reported at the time that both children were sick after leaving, having been left shocked by the aged state of a 17-year-old addict they met, the Princess said.

After declaring that he was going to start taking his law studies seriously, he was still spotted enjoying himself at party spots, drinking champagne and turning up for swanky gambling events at London clubs.

But after being caught taking cocaine in his early twenties, Frederick - known as Freddie - vowed to focus on his studies and later married glamorous actress Sophie Winkleman of Peep Show fame. 

Nicholas Knatchbull, King Charles godson and heir to the £100million Mountbatten fortune has struggled with drug addition.

The great-grandson of Lord Mountbatten - King Charles' godfather and very close confidante -  was Prince William's mentor at Eton.

But after leaving school, he became hooked on drugs, and dropped out of Edinburgh University after just six weeks. 

A typical evening out would involve drug-taking, nightclubs and often end with him performing dangerous high-speed manoeuvres in the car his father had bought for him.

He has previously boasted he allegedly gave Prince Harry his first cannabis joint when they were both pupils at Eton and how he smoked crack when the Queen came to stay with his parents at their mansion. 

Over the years, he has taken crack cocaine, heroin, ketamine and MDMA.

Devastated, his parents tried keeping him under curfew at Broadlands, the Hampshire home where the Queen and Prince Philip spent their honeymoon, but ended up sending him to detox clinics costing up to £10,000 a week in Essex, Surrey, London, South Africa and Arizona.

When he went on the run from The Priory, they had no choice but to have him sectioned under the Mental Health Act.

... but Kate is patron of a drug charity  

At the same time senior royals such as the Princess of Wales, are at the helm of anti-drugs charities. 

Kate has previously released a message of support for those suffering with addiction, urging them to not let shame hold them back from asking for help.

The Princess of Wales, patron of addiction recovery charity The Forward Trust, said addiction is 'a serious health condition' and 'not a choice'.

Her message of support for the Taking Action on Addiction campaign comes in the form of a video on the first day of Addiction Awareness Week.

In the video, Kate, now 42, said: 'Addiction is a serious mental health condition that can happen to anyone, no matter what age, gender, race or nationality.

'As patron of The Forward Trust, I have met many people who have suffered from the effects of addiction. Attitudes to addiction are changing.

(Fluierul)