A property owner was stabbed and beaten by thugs who had arranged to view his house.
Police say the victim was rushed to hospital after being attacked in his north west London home on Thursday afternoon.
He remains in hospital, but his injuries are not believed to be life-threatening.
A 29-year-old man was arrested on suspicion of robbery and possession drugs before being bailed.
Police say the drama began when the victim allowed two men and a woman into his house in South Harrow for a “pre-arranged” viewing.
A Scotland Yard spokeswoman said police were called just before 2pm on Thursday to reports of an assault inside a residential property in Northolt Road.
She said: “Officers and paramedics attended and found a man aged in his 30s injured, including a stab wound.
“The victim had pre-arranged a viewing of the property and to that end had let two men and a woman into the address.
“The victim was then assaulted by the men before all three made-off on foot. Nothing was reported stolen.”
She added: “Officers carried out a search of the area and a 29-year-old man was arrested on suspicion of robbery and possession of cannabis.
“He was taken to a north London police station and was subsequently bailed to return on a date in mid-March.”
By Stephen Beech