RCMP officers conducting a routine roadside stop in Manitoba last weekend seized a massive shipment of illegal cannabis products, police said Friday.

On July 20, a semitrailer was travelling to southern Ontario from Agassiz, B.C., on the Trans-Canada Highway when officers pulled it over near West Hawk Lake, about 140 kilometres east of Winnipeg, to inspect the driver's paperwork.

The inspection yielded a number of "discrepancies," Sgt. Scott McMurchy said at a news conference, with stacks of packaged marijuana on a table beside him.

Several officers examined the trailer and discovered the illegal cannabis — 420 kilograms of marijuana, as well as 75 kilos of shatter oils (concentrated cannabis extract), edibles and other products — hidden among a load of food.

"This seizure is the largest marijuana seizure through a traffic stop in Canada since 2015," McMurchy said.

Here's a video of the entire drug seizure:

A routine roadside stop leads to the largest marijuana seizure in Canada since 2015. 0:56

The driver of the truck has been charged with possession for the purpose of trafficking and trafficking an illicit substance. He has been released pending a future court date.

McMurchy said investigators are still working to determine the final destination for the cannabis, which was vacuum sealed and professionally packaged.

RCMP typically do not give estimated street value of drugs seized because prices vary across the country.

Though new legislation legalizing the sale of cannabis comes into effect in October, McMurchy said a seizure of this nature will remain illegal.

"It has been produced illegally. There is no way to know the origin of it, the potency without having it tested, or any risk of contamination."

While much of the goods seized — the dried cannabis — can be purchased legally this fall from sanctioned producers, edibles will remain illegal nationwide. People can bake and eat them on their own, however.

Winnipeg cannabis advocate Steven Stairs believes it's a matter of time until edibles also become legal, as there is a growing market for people preferring to ingest their buzz in a discreet snack, rather than smoking it.