Two reporters at the Edinburgh Evening News took to the city’s bars and clubs on a Friday night to investigate the extent of cocaine use in venues’ toilets.

Andrew Picken and Joanna Vallely visited 12 nightspots and found evidence of cocaine use in eight.

They used special field test wipes which turn blue when they come into contact with the cocaine.

Joanna said: "We went around various bars on a Friday evening - the bars didn’t know we were coming.

"We were not entirely surprised to find some evidence but we were surprised at the extent of it.

"In some cases there was just a wee trace but in others we were actually picking up powder."

Cocaine users often snort the drug off flat surfaces in toilet cubicles such as the backs of seats and toilet-roll holders.

Joanna said the bars seemed to be aware of the problem and that some have refitted toilet cubicles without any flat surfaces making it more difficult for drug users to snort cocaine.