TORONTO (Reuters) - It may be the effects of a hot real estate market in Toronto, but illegal marijuana growers appear to be looking at low-cost northern Ontario land as a way to cut costs, Canadian police said on Monday. In the past two weeks, police have made two massive seizures in sparsely populated towns in northern Ontario a region more famous for mining, timber and paper mills. About 39,000 marijuana plants, with a street value of more than C$40 million ($33 million), were seized in Iroquois Falls and Matheson, Ontario, about 650 km (400 miles) north of Toronto. The operations were about the size of three or football fields, police said. Those arrested were from Toronto, reports said. Police say the low cost of land is likely one reason grow ops may be moving away from the greater Toronto area, where nearly 5 million people live and real estate prices have been on a steady climb for years. "We're seeing an influx of people from the GTA. I think a lot of it has to do with the fact that you can buy land for pretty cheap here," Detective Sergeant Bill O'Shea of the Ontario Provincial Police drug enforcement unit said on Monday. "We're talking about a multimillion-dollar business." Growers may also be looking for locations further from the intense attention of law enforcement in and around Toronto, which has seen a series of high-profile busts in suburban houses or warehouses. Last year a virtual marijuana factory was discovered in an abandoned brewery just north of Toronto. The raid netted 30,000 marijuana plants from what police described as the biggest indoor grow op in Canada's history. The Canadian government is trying to toughen penalties for growing or selling the drug, but is also considering decriminalizing possession of small amounts of pot. This has drawn the ire of the U.S. government, which complains that Canada is too lax on drug use and has become a major source of the marijuana being smuggled into the United States. Studies estimate that illegal marijuana growers produce a crop with a street value of more than C$10 billion annually. Much of that is said to come from British Columbia, the country's westernmost province, which makes the potent "B.C. Bud," with much of it destined for the United States.