Detectives are investigating after a huge fire broke out in an isolated barn – alerting firefighters to a cannabis farm.

Six fire appliances from across West Yorkshire were called to Withens End Lane, Rishworth, at 8.20am on Sunday.

Watch Commander Alex Macfarlane, of Rastrick Fire Station, said: “Obviously with its location we were struggling for water supplies and we were there four hours putting it out.

“The fire appeared to have started in a caravan inside the barn and spread to another caravan nearby. The barn measured 60m by 40m and was situated 150m away from the farm.

The cannabis factory uncovered in Robinson Street
File picture of a cannabis farm

“Whoever has been running this cannabis farm has linked into the National Grid supply from a spur through to the mains and engineers from the National Grid have attended.

“The cannabis farm was accessed through a trap door and survived intact but the majority of the barn and both caravans were destroyed.

“Crews from Slaithwaite, Halifax, Huddersfield, Rastrick and Dewsbury attended and three hose reel and four breathing apparatus were used to fight the fire. Slaithwaite got there first.

“Fire investigators are looking into how it started. We are not sure who owns the barn.”

Mr Macfarlane said as many as 30 cannabis plants were recovered.