Police in Darlington have found what is thought to be the 'largest cannabis grow ever' discovered by the force.
Durham Constabulary were called to reports of the drugs farm at a property on Valley Street, in the town, just after 2.15pm on Monday 25 April.
Once inside, officers were confronted by about 3,400 plants spanning two floors of the unused office building.
Four men, aged 25, 27, 27 and 22, were arrested at the scene on suspicion of cultivation of cannabis.
They have since been charged and will appear at Newton Aycliffe Magistrates’ Court on Wednesday 27 April.
The force said a large police presence will remain in the area over the next few days.