Police are trying to trace a man who was seen to be kicked and punched before being forced into a car.
The victim, a black male thought to be in his twenties, was allegedly assaulted by two black males of a similar age in Wilson Grove, Southwark, south-east London, at 7.45pm on Monday.
He was seen being taken into a grey or silver-coloured two-door car, which was joined by a dark-coloured car, the Metropolitan Police said.
Both vehicles - each containing two males and one with the victim - then drove off towards Bevington Street.
Police are studying CCTV and have appealed for anyone with information to contact officers on 101, or phone Crimestoppers anonymously on 0800 555 111.