FIREFIGHTERS last night stumbled across a huge cannabis factory.

A crew from Brighouse Fire Station was called to the three-storey mill (pictured) in Hipperholme yesterday after reports of steam escaping from the top floor.

Watch commander Alex Macfarlane said: “There was a lot of steam coming out and all the windows were steamed up so we felt it necessary to gain entrance.

“It turned out to be a cannabis factory. The mill was full of about 400 plants.

“The ventilation systems were causing a lot of condensation.”

The firefighters phoned the police at 4.07pm after discovering the cannabis at the former Hipperpottery retail outlet on Gardiners Square off Denholme Gate Road.

Neighbourhood Policing Team members attended the mill last night.

Scenes of crime officers are due to go to the site today.