Illegal cultivation of marijuana in houses and apartments across Canada has exploded into a multibillion-dollar operation and is causing a headache for police and alarm in the real estate and insurance industries.
Most of the marijuana 'grow-ops' are in British Columbia and Ontario, but police say there are thousands in neighbourhoods across the country.
In a warning particularly to absentee and offshore landlords, police in British Columbia are urging owners to have an agent or friend check their houses regularly and advise police if there seems to be evidence of a grow-op.
To protect buyers, the real estate boards of Greater Vancouver and the Fraser Valley, the largest in British Columbia, have changed their 'property disclosure statement' so sellers will be required to indicate if a property has been used as a marijuana grow-op.
Another problem is grow-ops depend heavily on electricity that is stolen by means of illicitly by-passing the meters that measure consumption.
In Ontario police estimate electricity worth C$100 million ($653.55 million) is stolen every year.