A man armed with a knife and a gun allegedly threatened to stab a taxi driver in West Norwood in the early hours of the morning.
The driver called police at 2.25am on Monday (May 18) and told officers he had been attacked by a man with a knife on Knights Hill.
The victim did not suffer any injuries.
Following a foot chase, a 22-year-old man was arrested in nearby Leafield Close.
He was arrested on suspicion of possession of a firearm, possession of an offensive weapon, possession of class A drugs and attempted GBH.
"He remains in custody at a South London police station," a spokesperson for the Metropolitan Police said.
"A firearm, a knife and a quantity of class A drugs were recovered by officers.
"Enquiries into the circumstances continue."
Anyone with information is asked to call 101 or contact police via @MetCC.
Alternatively contact Crimestoppers anonymously on 0800 555 111.