Police have seized more than 30 guns at an address in east London in one of the biggest ever haul of firearms.
Assault rifles, sawn off shotguns, an Uzi and a Thompson machine gun were among the weapons found in Leyton.
A vast quantity of ammunition was also discovered.
A 51-year-old man was arrested at the address and remains in custody.
Officers from the Waltham Forest Gangs Task Force are investigating the circumstances behind the discovery.
Acting Detective Superintendent Gary Bruce said: "Seizing guns has helped us vastly reduce gun crime across the capital.
"The size of the seizure is exceptional and the danger of the these weapons in the wrong hands cannot be overestimated."