The largest cannabis farm and factory ever uncovered in Northamptonshire has been found in two terraced houses.
Rows of cannabis plants which were found on the premises
Around 4,000 cannabis plants were found at at the properties in St George's Street, Northampton, by police officers following a tip-off.
More than 40 rooms in the premises were used to grow cannabis although no one was present when police arrived.
Officers also discovered rooms with drying cannabis leaves and sacks of herbal cannabis ready for sale.
Around 12 police officers and police forensic science investigators have been working at the scene since Tuesday night.
Ch Insp Dave Hill said: "We are still at the building and working through what is there but already it is clear that we have uncovered an organised cannabis production factory that was working on a major scale."