Police have appealed for clubbers who may have felt ill

Russell Johnstone, 19, from Alloa, collapsed at the Arches in the city centre in the early hours of Sunday.

He was treated at hospital but died on Tuesday. Officers are waiting for a toxicology report to confirm whether the class A drug was to blame.

The possibility a dangerous batch of the drug is in circulation has not been ruled out.

Police appealed for information from any other clubbers who might have taken ill after taking something at the popular dance venue.

Detective Sergeant Alan Brown, of Strathclyde Police, said: "I'm keen to speak to any patrons who attended the Arches nightclub on Saturday and who may have consumed substances which resulted in them feeling unwell or requiring medical treatment."

Mr Johnstone worked as a trainee at an Arnold Clark car showroom in Glasgow.

Colleagues paid tribute to the teenager.

An Arnold Clark spokeswoman said: "Russell has worked with us for the past six months and he had a fantastic career ahead of him.

"It is a tragedy and we offer our sincere condolences to his family and friends."