More than 15,000 cannabis plants with a street value estimated up to £4m have been found at an industrial unit in North Lincolnshire.
Three men charged over the discovery of the 15,000 plants in Park Farm Road, Scunthorpe, may have been victims of human trafficking, police said.
The men were charged with producing a controlled drug and are due at Grimsby Magistrates’ Court later.
Police said the case had been referred to the National Crime Agency.
Humberside Police said the plants – found on on Monday – had been in various stages of cultivation.
Along with the equipment, the plants have been removed for destruction, the force said.