British police investigating drug-related killings in London have found hundreds of guns in three raids on addresses in Kent
Law enforcement agencies in the United States were conducting a linked operation in New Jersey.
"This is the biggest firearms haul we have ever had," Detective Chief Superintendent Kevin Davis told the Evening Standard.
Officers raided two residential and one business address in and around Dartford at 6 a.m.
At a semi-detached home in Dartford opposite a primary school, they found hundreds of firearms, including shotguns and automatic and semi-automatic weapons.
"Guns are mounted on every available wall space in the property and live ammunition was found lying on the floor," said Davis.
"It will take us at least three days to log it all and bag up all the evidence."
The arrested man was held on suspicion of supplying firearms.
The Evening Standard said the man was believed to be a registered firearms dealer but Davis said hundreds of the weapons found in the house were illegal.
Scotland Yard said the searches were the culmination of a major operation -- codenamed Mokpo -- launched after a spate of gangland shootings in north London.
The raids had been planned for 18 months and were conducted by officers from the Yard's Operation Trident section, which targets gun crime and drug-related killings in the black community.
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