MONTREAL -- Montreal police are warning the public about an ongoing fraud scheme targeting Desjardins clients over the age of 75.

Police say two fraudsters are pretending to be a Montreal police officer and a Desjardins advisor in order to obtain victims' credit or debit cards and personal information.

The fraudsters call the seniors on the phone, telling them they have been the victim of a fraud. In order to help the so-called "investigation," the fraudsters tell them they must place their debit and credit cards in an envelope marked "SPVM" and place them in their mailbox.

They tell the victim that a police officer will drop by quickly to collect the envelope. In some cases, fraudsters also request the card's PIN, still claiming that it is for the purposes of an investigation. The fraudsters then pick up the cards and use them to make purchases.

Of note, police said, is that the fraudsters are aware of certain bank transactions made by the victim and mention them during the call in order to add to their credibility and gain trust.

Montreal police say if you receive a call claiming to be from police or a banking representative asking you to hand in your debit or credit card, hang up and call 911 to report the incident.

Do not give your cards and personal identification numbers to anyone under any circumstances unless you are at your financial institution or you have contacted the police yourself.

Police are asking anyone who has been a victim of this fraud scheme to file a complaint by calling 911.