About 1,800 marijuana plants worth an estimated $1.8 million were seized from an illegal outdoor grow operation in Algonquin Park last week.

Ontario Provincial Police received an anonymous tip about the plants on Sept. 18.

The next day, at least four officers from the Killaloe OPP detachment went to the scene and removed the plants.

Each plant was estimated to have a street value of about $1,000, or $1.8 million in total, OPP said.

The plants are being destroyed.