Police poured into a Penryn industrial estate this afternoon during a firearms raid as part of a Metropolitan Police case.
Firearms officers were on scene, along with police vans and several unmarked cars, while witnesses reported seeing dog units arrive at the West End industrial estate.
One witness said around 40 officers took part in the exercise, targeting a premises which is part of unit four on the site.
Chris, a worker at another unit on the site, said: "It's the fourth time it's been raided. There were about 40 officers there altogether.
"They didn't turn up with sirens or anything.
"I know they had the dogs up there, and the rest of it."
A spokesperson for Devon and Cornwall Police said: "Officers from the force have this afternoon assisted officers from the Metropolitan force who have arrested a 44 year old man on suspicion of firearms offences.
"Officers also assisted during a search of a premises in Penryn."
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