Authorities have seized more than 50,000 bogus cheques intended to be used in a mail scam, RCMP in Montreal said Tuesday.

The Centre of Operations Linked to Telemarketing Fraud (COLT) -- a joint forces operation headed by the RCMP -- seized the cheques in a one-month blitz.

The COLT specialized team launched its investigation after Canada Post Security and Investigation Services intercepted envelopes with forged postmarks.

"In this period of one month from Nov. 14 to Dec. 14, we've intercepted over 50,000 letters for a grand total of the fake cheques that were in these letters totalling $195 million which is astronomical for a one-month period," Sgt. Tony D'Angelo, of the RCMP fraud unit told CTV's Canada AM on Wednesday.

The surveillance operation led to the discovery of 50,065 fraudulent letters, accompanied by the bogus cheques, being sent to American and Canadian citizens.

The letter informed recipients that they had won a prize of up to $50,000.

To collect their prize, the recipients were told they had to cash the accompanying bogus cheques -- which ranged from $2,000 to $5,000 -- and return part or all of the money to pay for administration fees under an "international consumer protection act."

The recipients were given only a short time period to send the money, preventing the recipient's bank from certifying the cheque.

As a result, the victims would send the money to postal boxes or wire the money electronically only to realize later that the deposited cheque they received had bounced.

No arrests have been made in the case but the investigation is ongoing, RCMP said in a press release.

In a statement, the RCMP warned the public that "money should never be sent to a company or a contest to claim an alleged prize" and said this type of mass marketing fraud "knows no boundaries" and is growing."

D'Angelo said people should be suspicious when mail arrives on their doorstep telling them they have won a prize in a contest they didn't enter. 

"People must ask themselves, why is someone sending me a cheque? Have I applied for a lottery? Why is somebody sending me winnings and number two why are they sending me money that they want me to send back? If they're the lottery, why am I sending money back?" D'Angelo said.

In a statement, the Mounties warned that they take mail fraud seriously.

"Mass marketing fraud is a serious crime often committed by structured criminal operations," the RCMP said in a statement.

"The consequences of this form of economic crime, against persons or businesses, are devastating for the victims and consumer confidence."