Thousands of the powerful pills - which have been linked to a man's death - are feared have been shipped into the country.

Drugs squads across the country are being extra vigilant after the tablets were linked to the death of the 45-year-old in England.

But one police insider described the effects of the pills as "particularly nasty".

They added: "Tests are being done on the recovered tablets at the moment.

"We all know ecstasy is dangerous, whether they are pink, red, green, blue, yellow, or stamped with a logo or not.

"But these are particularly nasty."

Supplies of the small turquoise pills - which are shaped like a shield - have been found in Scotland.

Officers immediately warned people not to take the pills, which are sometimes known as Turquoise Heart.

Police in Glasgow have repeatedly warned about the dangers of "party pills" and so-called legal highs.