A 23-year-old man has been charged after police recovered a Scorpion sub-machine gun and bullets at a house.
Spencer Inglis, from Mitcham, was arrested during a midnight police raid in Commonside East on Friday, April 11.
Mr Inglis and eight other people aged between 18 and 54 were arrested on suspicion of firearms and drugs offences and remanded in custody.
The other eight people have been bailed until a date in July while police investigate.
Mr Inglis appeared in Wimbledon Magistrates' Court on Monday, April 14, charged with possession of a firearm with intent to endanger life, possession of a prohibited firearm and possession of prohibited ammunition.
He has been remanded in custody to appear in Kingston Crown Court on April 28.