Saskatchewan police can't confirm it, but a former Regina drug dealer says some of the marijuana on the streets has been laced with harder drugs like crystal meth and cocaine.

Sean Perreault, 16, says he used to add small quantities of the harder drugs to the pot he sold. He says that although he's no longer involved in dealing, the practice is still happening.

Perreault, who says he has never been charged with a drug offence, said he added other drugs to the marijuana so customers would prefer his supply — or become addicted to it — and buy only from him.

"You'd go through more laced pot than you would normal pot," he said. "You'd go through it quicker and sell it quicker."

Sgt. Jerome Engel of Saskatoon's integrated drug unit says lacing is another reason to be wary of buying marijuana.

"Source information tells us that people do that, but I can't confirm it," Engel said. "It isn't something I think would be popular, but it can be done."

From a business perspective, adding crystal meth to marijuana doesn't make a lot of sense, he said.

"They're putting a lot of money into a cannabis marijuana joint that's going to sell for $5 to try and get someone addicted," Engel  said.

He noted that said smoking laced marijuana could have serious side effects, including becoming addicted to crystal meth or cocaine.

Drug enforcement agencies have warned that crystal meth labs often use caustic chemicals in the manufacture of the drug — everything from drain cleaner to battery acid.