Calgary police say more than $1.6 million has been stolen this year from approximately 122 seniors in the city by fraudsters using what is known as the grandparent scam.
Police say in a statement there has been a sharp increase in cases this month, with 93 reports involving 35 victims losing money to scammers.
Three people have been arrested and charged within the last few weeks but have since been released on bail.
Police say victims are typically contacted by phone by someone impersonating a relative, police officer, lawyer or bail bondsman and are told that a loved one is in need of financial help in the form of bail money or legal fees.
They believe scammers are able to collect detailed information about victims that lend credibility to their stories but investigators have not confirmed how the information is being accessed.
Police say one victim was defrauded of nearly $300,000 in August.