Two men have been arrested by police investigating a kidnapping ordeal that lasted 50 hours.
The 24-year-old victim was stripped naked, tied up and beaten after being lured to a house in Thornton Heath, Croydon by two acquaintances.
He was set up by an armed gang who took his keys and burgled his parents' home.
Two men, aged 29 and 19, have been arrested on suspicion of kidnap after CCTV was released in a public appeal by the Met Police.
The pair are being questioned at a south London police station.
Police said they were hunting for another two suspects in connection with the "vicious and prolonged attack", which may have involved up to 12 attackers.
The victim was lured to a house while he was walking along London Road at 2pm on Monday.
As well as his £9,000 Rolex watch, a significant amount of cash was taken from his parents' property in Sydenham, south-east London, police said.
'Utterly distraught '
The captors had previously forced the man to ring his parents and make a ransom demand for his release, which they could not pay.
On Wednesday, which was the third evening of the hostage ordeal, the victim was taken by car to a Metro bank cash machine in North End, Croydon, so he could withdraw money.
His tormentors waited in the vehicle, apparently out of fear of being captured on CCTV, giving the man an opportunity to escape.
Two men, aged 39 and 58, were previously arrested on suspicion of kidnapping and bailed to January.
Det Sgt Samuel Bennett, of the Croydon Criminal Investigation Department, said: "This was a vicious and prolonged attack of a nature that thankfully is very rare.
"It has left the victim utterly distraught and traumatised."
The entry of two suspects into the home of the victim's parents was captured on CCTV. The footage has been released by police in a bid to identify them.
"These men are dangerous and it is important that we apprehend them before they can target anyone else," Det Sgt Bennett added.