Police say the two claimed to have been raising money for the Dr. Julien pediatric foundation and for L'Itinéraire, a magazine that benefits the homeless.
They say the man and woman collected donations for months near metro stations and on the street.
However, police say the money never went to either of those charities.
The pair were arrested Saturday morning in downtown Montreal.
"The investigators in that case are still looking for potential victims in that case. So [to] any persons that gave them money: the money did not go to the foundation," said Const. Daniel Lacoursiere.
Lacoursiere said the man and woman — who are both in their 40s — allegedly collected money from residents in the Hochelaga-Maisonneuve borough and Le Plateau-Mont-Royal.
Both suspects were arrested and let go with a promise to appear in court.
Dr. Julien Foundation says it does not ask for donations on the street or go door-to-door, with the exception of an annual food drive in December.
The police are now asking people who have donated money to these people to come forward.