Cannabis plants with a street value of £1.5m have been seized as part of a police operation to deter criminals from abroad.
The crop of more than 3,500 plants, of which 1,700 were mature, was found in a warehouse off Fleming Road, Waltham Abbey, Essex, on 21 October.
Two Albanian men were charged with cultivating the plants.
A total of 15 foreign nationals were arrested by Essex Police as part of the nationwide Operation Trivium.
They included a Vietnamese woman and two Vietnamese boys aged 16 and 17, who were arrested on suspicion of immigration offences in Colchester.
Two men and a woman, all from Albania, were arrested on suspicion of being illegal immigrants after they were seen running away from Purfleet dock, police said.
Ch Insp Jon Hayter said: "Essex has a major airport, sea ports and important road links to ferry ports in Kent and Suffolk.
"Much of the work of Operation Trivium was related to detecting or deterring offenders coming into our county to commit their crimes or using our roads to go to other areas."