A reporter from UK paper 'The Daily Mail' went undercover to expose what goes on behind the closed doors of Britain's most exclusive clubs.
One of these was the nightclub Boujis, where William and Harry have often been photographed with their girlfriends and close set of acquaintances.
The undercover investigation revealed that the club was a retreat for young people looking for cocaine induced high.
In her investigation, the reporter, who posed as a fashion student living off her millionaire father's money, wiped the surfaces of toilet lids and toilet roll covers with a special cocaine identification kit on four occasions.
According to the reporter, Nark Cocaine ID Swipe, supplied by drug testing specialists Drug Aware, are used in America by forensic teams, and these "wet wipes" can test for even the tiniest traces of cocaine and crack cocaine.
After she wiped the wet wipes, they immediately identified cocaine as the substance present.
In one instance, the toilet roll holders were smothered in large white chunks, which also tested positive for cocaine.
However, Boujis manager Jake Parkinson-Smith, said, "We have a zero tolerance policy against any type of drug at Boujis. Anyone found with drugs is immediately ejected and the police informed."
Boujis was the place where Prince Harry once famously cavorted with a television presenter and was photographed with his hands over her breasts.
The club was also where the 23-year-old allegedly attacked awaiting paparazzi.
William was photographed at the club last week with Kate Middleton, confirming rumours of their rekindled romance.
Other clubs which have been affected by cocaine use, and which are constantly infested with celebrities, have been forced to remodel their bathrooms.
At Mahiki, often frequented by Sienna Miller, Kate Middleton, Princess Beatrice and the children of Richard Branson, the owners have built toilet cisterns into the wall, eliminating a large flat surface to snort the drug off.
Attendants are also on hand to stop people going into the toilets in pairs.
But, like Boujis, drug users at Mahiki have made good use of a five-centimetre long, three-centimetre wide toilet roll cover, the report said.