A total of 322 cannabis plants were seized from the property after a lack of snow on the roof of the building aroused police suspicion, pointing to the heat produced by professional growing operations.

West Yorkshire Police said there was also a strong smell of cannabis coming from the unassuming house in Keighley.

No arrests have been made as there was nobody home at the time of the raid, but investigations are ongoing, the Daily Mail reports.

Some of the seized plants were as tall as six foot, officers said.