Cannabis plants with a street value of more than half a million pounds have been found in underground bunkers constructed from shipping containers.
Police raided a farm at Skendleby, Lincolnshire, after being tipped off by their counterparts in Spain.
Officers not only found the containers buried 20ft underground but 300 tonnes of illegal waste, 22 horses, six stolen cars and a Llama.
Three men have been arrested and released on bail.
Lincolnshire Police spent nine days searching the site after it was tipped off by the Guardia Civil that a drug operation was taking place at the farm.
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After discovering the entrances hidden in barns, officers found four underground bunkers.
Inside 12 containers used to make up the bunkers officers found “a large number of cannabis plants” with an estimated value of around £580,000.
Along with the tonnes of illegal waste, the search teams also found 60 part-dismantled vehicles, used asbestos roofing materials and evidence of areas being used to burn waste illegally.
The three men, aged 34, 35 and 28, were arrested on suspicion of producing a Class B drug, burglary with intent to steal and animal welfare offences.
The 34-year-old was also arrested on suspicion of having a prohibited firearm and theft of a motor vehicle.
Lincolnshire Police said those responsible for the waste being at the site faced a bill of around £100,000 for its removal.
Det Supt Rick Hatton said: “We are extremely grateful to our counterparts in Spain and our partners for assisting with the exploration of this site.
“With the operation being underground we have needed some real specialist support to uncover this activity.”
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