Police swooped on five stores – including Stuff in the city centre – in a bid to combat the sale of the mind-altering substances.

A team of around a dozen plain-clothed officers entered the Union Street shop, which sells bongs, pipes, herbs and legal highs, and spent around six hours inside.

Officers from Strathclyde Police targeted "legal high hotspots" during the day of action, which started early yesterday.

The Evening Times was given exclusive access to the operation, as a team of officers raided the shop.

The squad took away more than 20 evidence bags packed with items including packets marked "Dutch Dragon", "Paradise Seeds" and paraphernalia.

Some bags also appeared to hold packets containing herbal substances.

All evidence recovered was then taken to a city police station for tests.

Police have not yet revealed the location of the other four stores.

A website for Stuff states: "Our shop is unique and offers highly sought-after products." The shop was closed for much of yesterday, with heavy steel shutters in the windows and blocking the door.

The raids come after the death of a teenager at the RockNess music festival.

Alex Heriot, 19, from Portobello in Edinburgh, collapsed on Saturday June 9, at the three-day festival on the banks of Loch Ness after taking a chemical called Benzo Fury, similar to banned substance mephedrone.

He was taken to Raigmore Hospital in Inverness where he died hours later.

There is no evidence Alex purchased Benzo Fury from any of the Glasgow stores targeted yesterday.

However, police want to spread the message that so-called legal highs are not safe. A spokeswoman for Strathclyde Police said: "Officers have carried out an operation under warrant at premises in Glasgow in connection with psychoactive substances. Inquiries are ongoing."

rebecca.gray@ heraldandtimes.co.uk