A £2m cannabis farm "the size of a football pitch" has been discovered in Gateshead.
Northumbria Police say a farm containing an estimated 3,000 plants worth about £660 each were discovered in the Team Valley trading estate after a police officer noticed a strong smell.
Community Support Officer Martin Jobling had been on patrol at the Valentine’s Funfair on Team Valley and noticed a strong smell of cannabis. With the help of Acting Inspector Warren Sturrock he identified a warehouse which seemed to be the source of the smell.
Inside they found the plants and a number of people, and arrested three foreign nationals on suspicion of producing a Class B drug with intent to supply.
Workers and business owners on the Team Valley were "shocked" to see the large-scale police operation, which began on Thursday and continued on to Friday afternoon.
Rajan Jerath, who runs BeBe clothing on the trading estate, saw the operation in progress as he left his office to send some post.
He said: "It's shocking to see it so close to our offices - very alarming.
He added: “We’ve been here 15 years and you get the odd speed camera van but never anything like this.”
Brian Short, who works nearby, said he and his colleagues had seen officers removing "large green plants" and plant pots on Friday morning, after spotting a large amount of police activity there on Thursday night.
The three men arrested are currently in custody, and a criminal investigation is ongoing.