A makeshift cannabis factory has been closed down after police investigating residents' concerns noticed that its hothouse growing conditions had melted the snow on its roof.
Leicestershire Police said heat-generating lights used at the house were thought to have melted the snow, distinguishing the property from surrounding buildings.
More than 300 cannabis plants, worth tens of thousands of pounds, and a range of sophisticated growing equipment were found yesterday after a search warrant was executed at the house in Montrose Road, Leicester.
A police spokesman said members of the local community had reported suspicions about what was happening inside the rented house, which has been left badly damaged.
The spokesman said: "When officers began checking out the information, they noticed the house was one of the few in the area without snow on the roof.
"Cannabis factories tend to be very warm due to the high number of industrial-strength lights used to encourage plant growth."
No one was in the house at the time of the raid and no arrests have yet been made.
Pc Chris Gerrard, from Welford Road local policing unit, said: "We would like to thank the members of the community who contacted us with their concerns.
"By closing this drugs factory we have disrupted a significant criminal enterprise and stopped a large amount of drugs from reaching the streets of Leicester."
Pc Gerrard added that - apart from the absence of snow - there were a number of factors neighbours could look out for that might indicate a cannabis factory had been set up, including permanently obscured windows and heavy condensation.