Toronto police have busted a large marijuana grow-op that was housed inside the maintenance area of an east-end condominium building.

Police raided the grow-op on Monday, seizing 2,674 marijuana plants worth an estimated $2.5 million on the street.

Officers also confiscated what they described as "a large quantity of hydroponic equipment."

Police said the building was located in the McCowan Road and Highway 401 area.

The investigation is still ongoing and police say they are still trying to round up several suspects.