Hundreds of guns andthousands of rounds of live ammunition were seized by police yesterday in a dawn raid on a semidetached suburban house.

Twelve Operation Trident officers entered the fourbedroom property in Dartford, Kent, at 6am and unearthed a cache of pump-action shotguns, automatic and semi-automatic weapons.

The Metropolitan Police described it as the biggest weapons haul in the force's history but conceded that some of the guns may be legally registered.

Plain-clothed officers arrested a 55-year-old man at the house on suspicion of supplying firearms from a residential address and took him to a north west London police station.

The property is listed under the name of Michael Shepherd, a registered gun dealer, who runs a web site advertising the guns he sells.

Mike Yardley, from the Shooting Sports Trust, said Mr Shepherd was well known as a gun dealer and collector.

"He specialises in weapons from the Victorian and Edwardian period and typically holds a very large stock.

"The man has been operating a website where he has been advertising his wares for a significant period of time."

Mr Yardley described him as a kindly but eccentric man of Asian descent who is a devout Catholic and loves Elvis Presley.

"He is very hospitable but rather an eccentric chap. I have been struck by the extent of his collection, which is historically significant."

In the raid, a second home and a business address nearby were searched, with four guns discovered at the house. A "substantial" amount of cash was found at all three premises.

At the house in Dartford, thousands of rounds of ammunition and a number of weapons were removed by police, including M16 rifles and revolvers in see-through plastic bags.

A police spokeswoman said the man arrested was believed to have a gun licence.

Operation Trident was set up in 1998 in response to a spate of shootings and murders within the black community in the London boroughs of Lambeth and Brent.