Cpl. Darleen White said Friday the email messages to Canmore near Banff National Park contained threats of violence.
She declined to provide more details.
The people who sent them could be charged with uttering threats under the Criminal Code, a charge that carries a maximum penalty of five years in jail, she said.
Canmore has hired a contractor to trap the hoppers, which have been multiplying like rabbits in the years since wildlife officers killed coyotes in the area.
The town says the trapped rabbits will be gassed unless a responsible group is willing to sterilize and relocate them.
Animal welfare groups, including Save Canmore Bunnies, have been lobbying against the plan.
A website also urges tourists to boycott the scenic Rocky Mountain community if it doesn't back off plans to destroy the rabbits. Save Canmore Bunnies says it has nothing to do with the website.
Town officials declined to comment on the threats other than to say they have been referred to police.
Earlier this week, Mayor Ron Casey said trapping the rabbits could start next week.
Casey has said the rabbits are too plentiful and could attract predators. Earlier this year, Alberta wildlife officers shot two cougars near the community.