A cannabis factory with a crop estimated by West Midlands Police to have a street value of £3m has been uncovered inside a listed building.
A spokesperson for the force said the cannabis plants were found across three floors, the loft space and clock tower at Haliburton House in West Bromwich.
Police also found an extensive heating, lighting and hydroponics set-up.
It was discovered on 14 July when a utilities company reported a surge in electricity usage at the building.
The force said thousands of plants, many approaching maturity, were being cultivated throughout the Grade II listed Victorian property which was previously home to a metal manufacturing firm.
Det Insp Ade George said: “We strongly suspect this drugs factory, given the scale, is linked to serious organised crime.
“It’s a big win for us and its discovery, especially as the crop was nearing harvest, will be a significant dent in the finances of the crime group involved.
“We’ve seized several million pounds worth of drugs plus equipment also costing tens of thousands of pounds.
“A drugs factory of this size, with all the modifications, takes a lot of time and effort. I would suggest it has been in operation for around six months. There is also clear evidence of living quarters within the property.”
Due to the level of contamination at the site, the force said all recovered material would be classified as contaminated waste and disposed of safely.
No arrests have so far been made. West Midlands Police has urged anyone with any information about the discovery to contact them.