PEMBROKE, Ont. - Police in eastern Ontario believe they've busted the largest marijuana grow operation in Canadian history.

More than 40,000 plants were seized after provincial police raided a farm in Laurentian Valley Township, just outside Pembroke, Ont., last Thursday.

Numerous officers were called in over the weekend to help recover the plants as well as some farming equipment.

Police say plants were growing between corn stalks, and an irrigation system ran through the property from a pond and an above-ground swimming pool.

Supt. Frank Elbers says it's the largest marijuana grow operation the force has seen since the former Barrie brewery plant operation in 2003, which saw some 30,000 plants seized.

No arrests have been made.