|Thermal imaging cameras are being used by police to reveal homes concealing secret cannabis factories.|
The hand-held equipment detects the extreme heat created by lighting systems used in the intensive rearing of marijuana plants.
Properties where cannabis is being grown will release up to 10 times the amount of heat of an average family home.
Police said the crop from just one house can be worth more than £70,000.
Officers in London have successfully used the cameras for the first time in the Haringey area of the capital.
They patrolled residential streets looking for suspicious heat emissions from buildings.
Officers seized a "significant" amount of cannabis and drugs paraphernalia after raids on two properties today.
Sergeant Ian Pyles, who led the operation from St Ann's Road police station, said: "This latest technology has allowed us to quickly identify houses in Haringey which have been turned into cannabis factories.
"The equipment means we can covertly film a line of properties and identify the factory when the thermal image glows white-hot.
"In some cases, so much heat is being emitted that the house will look as though it's ablaze."
He added: "With one house crop of cannabis being worth in excess of £70,000, we have to work hard to put the growers out of business.
"Drugs in local communities can ruin lives and we are determined to improve the borough for the benefit of everyone."
The two raids today took place at homes in Braemar Road and Roslyn Road in South Tottenham.
Haringey borough commander Simon O'Brien said: "We work hard to make Haringey one of the safest London boroughs and will use all means to help us achieve that goal.
"This type of technology is the way forward for the Met and will ensure that we stay one step ahead of the criminals and drug dealers.
"The camera, supplied to the Met by Devon-based Frontline Products, is currently being piloted in Haringey and is due to be used for several future operations."