Ontario Provincial Police have seized more than 1,000 kilograms of pure cocaine in what the force is describing as the "largest single drug seizure in OPP history."

The seizure took place in the course of a multi-jurisdictional investigation that followed the cocaine from Argentina to the Port of Montreal, where it was sent to Ontario to be distributed.

"We've never seen anything like this in a single seizure," said OPP deputy commissioner Rick Barnum at a Monday morning press conference in Orillia, Ont., at which he sat in front of a wall made of the seized bricks of the drug.

The OPP estimates the 1,062 kilograms of cocaine seized would have had a $250-million street value once cut.

Cocaine arrived in shipping containers

In addition to the OPP, the Canada Border Services Agency, Peel Regional Police, and Financial Transactions and Reports Analysis Centre of Canada (FINTRAC) all collaborated in the investigation, which was called Project Hope.

Barnum said the drug came from Argentina in shipping containers, was sealed into concrete blocks, and packed onto pallets in a way that made the contents extremely difficult to detect.

The OPP released this image of concrete that encased a brick of cocaine during transportation from Argentina. (Ontario Provincial Police)

He said that it's unlikely the cocaine was produced in Argentina, which he described as a "transportation link" country.

"I can't say the source of the cocaine as to where it was produced," he said, adding "there are connections to Mexico and the Mexican cartels."

Police say various caches of cocaine were found at the Port of Montreal and in Stoney Creek, Ont.

Three Canadians face charges

As a result, three Canadian men are facing charges of importation and possession with the purpose of trafficking.

Luis Enrique Karim-Altamirano, Mauricio Antonio Medina-Gatica, and Oban Orozco-Lomeli, the three men facing charges, are all originally from the Greater Toronto Area.

Police say there is no evidence at this time of corruption at the Port of Montreal, where the drugs passed through.