CRIME gangs have begun importing "luxury" high-grade Moroccan cannabis resin, or hashish, to compete with Scotland's homegrown grass.

Police have seized hundreds of kilos of so-called pollum hashish – which is essentially the "extra virgin" version of the drug – in recent months.

Sources say the product is so much stronger than the usual low-quality resin historically sold in Scotland, that some users are vomiting and passing out after using it.

Resin – traditionally sold as relatively cheap "soapbar" – has lost market share north of the Border in recent years to herbal cannabis, or grass, grown in secret cultivations or farms in the UK.

Now, importers are trying to lure them back to resin by selling the high-quality "pollum" variety, which is often called "pollen" on the street.

Detective Sergeant Michael Miller of Strathclyde Police, an authority on the Scottish drug market, explained: "We have had significant seizures in the hundreds of kilos of better-quality resin. This is something we have had real success with recently.

"They call it pollum and it is Moroccan-produced. That is what is out there.

"People perceive resin as rubbish but marketing – and remember organised crime is a structured business and will market its products like anyone else – has now got the better stuff out there.

"It is all about supply and demand. All organised criminals care about is profit."

Until now, much of the cannabis resin in Scotland has been of very poor quality.

Sold as a ninebar – nine ounces or 250g – the product was far weaker than much of the herbal cannabis produced over the course of the last five or six years in secret farms, often by Chinese organised crime groups using slave labour trafficked into the country.

Miller added: "Most of the cannabis resin we used to get was also from Morocco but it was perceived as not as good quality as herbal cannabis.

"The resin manufactured there was full of adulterants.

"Think of resin as being like olive oil. Pollum is the extra virgin stuff, made out of the first press – slate is the second press. The cannabis resin we usually get is the rubbish that is left, like cheap cooking oil."

Sources say some users are suffering "whiteys" – effectively a cannabis overdose that can leave a user unconscious – after using the new high-grade pollum.

"It is a bit like seeing a tourist walk out of a cannabis cafe in Amsterdam and vomit," said one source. "Our dopeheads can't tell the difference between pollum and soapbar to look at and a few of them have come off the worse for wear.

"The real cannabis connoisseurs would never touch resin, which they think is just for neds and students."

As revealed in this newspaper last year, the Scottish market for herbal cannabis has become more and more sophisticated.

Brands of herbal cannabis such as AK47 can command high prices, up to £340 an ounce, compared with £170 for a standard mid-quality product.

Users compare such drugs to fine wines and seeds for different cannabis plant varieties are freely sold in both "head shops" and online.

Most of Scotland's cannabis cultivations produce the standard-grade drug, however.

Until recently, this was linked with Chinese and southeast Asian organised crime groups. However, Miller stressed indigenous Scots were now moving in to the industry, too.

He said: "If a particular ethnic group is making money out of an activity, it won't be long before others follow suit."