More than £1 million-worth of cannabis has been found growing in a former bank.
Some 2,000 plants were found in the makeshift cannabis factory in Bedminster, Bristol, on Wednesday.
The haul at the disused bank building in East Street is among the largest in the history of Avon and Somerset Police.
Around 60 bags of soil and 150 lights and transformers were also found in the "sophisticated set-up".
Two men aged 29 and 30 have been arrested on suspicion of production of a controlled drug and are in police custody helping officers with their inquiries.
Sergeant Jon Bane said: "This is a large-scale sophisticated set up capable of producing many thousands of plants. This operation should send a strong message that drugs will not be tolerated in Avon and Somerset.
"I would urge the communities to continue to help us by reporting any information they have. I assure you that it will be met with a positive police response."
Officers were acting upon information obtained by the Metropolitan Police Service.Reuse content