Police have arrested four men in connection with last week's brazen theft of 16 tonnes of silver from the Port of Montreal.

Const. Anie Lemieux says the men will be questioned overnight.

Lemieux says some of the loot has been recovered by investigators as well.

"They found silver bars during their searches, but we do not have a count on how much silver has been found so far," she said.

"They are actively searching locations on the island of Montreal, mostly on the western part of the island."

The heist took place last Wednesday, when one or more individuals stole a semi-trailer truck from Montreal's west end, drove it to the Port of Montreal, loaded a shipping container holding up to $10 million in silver onto it and took off.

The container lifted from the port was found empty Saturday on a residential street in Repentigny, a small city just off the northeast tip of the island of Montreal.

Lemieux said the public was helpful to police in moving the case forward.