ONE of Bolton’s biggest ever cannabis farms has been found in a disused mill in Great Lever.

Police found the 1,000-plant operation after raiding Grecian Mill in Lever Street at about 10am today.

They then came across a second farm in a building next door, which they estimated contained another 500 plants.

The second factory was described by officers on the scene as a “very sophisticated” operation, contained in several rooms and complete with living quarters.

A large quantity of cannabis had already been harvested and was ready for sale.

In total, the drugs found across the two farms are worth nearly £1 million.

The two farms are believed to be linked to each other, with some drugs thought to have been moved between the two buildings, police said.

Police also said the operation had the potential to be the “biggest ever” they have found in Bolton.

The mill raid was prompted by calls from concerned residents.

Three men, aged 29, 48 and 58, along with a 47-year-old woman, have been arrested at the scene on suspicion of producing cannabis.

They are all in police custody.

Det Sgt Martin Ashurst, based at Scholey Street police station, said: “We are currently working to remove these two large-scale cannabis farms from the building and have four people in custody that we will be questioning about this discovery.

“Tackling the production, sale and supply of drugs on our streets remains an important issue for us in Bolton, as we know that drug-related activity is a blight on our communities and is something we will simply not tolerate.”

The second farm included full living quarters and showers, indicating that people stay on the site of the operation.

The landlord of both buildings affected came to the scene to help police with enquiries.

It is thought the growers had illegally gained access to the buildings to set up the operation.

In addition to the huge number of plants, equipment needed to grow the drugs was discovered in huge quantities, including a large amount of soil at the second location.

Police said they will be investigating over the coming days to see if the growers are running even more farms.

One plant is worth approximately £400 to £500, meaning the two farms carry a flat street value of up to £750,000.

When the bagged, harvested drugs are taken into account, that figure is considerably higher, while the farms would have had the potential to yield £3 million over 12 months, with the plants typically cropped four times per year.

Anyone with any information about drug-related crime in Bolton can call police on 101, or contact Crimestoppers, anonymously, on 0800 555111.