A woman entered a house in south London “with a big smile on her face” just 25 minutes before a 19-year-old woman was found fatally stabbed, neighbours have said.
Police were called to a property in Ash Tree Way, Croydon, at around 4.10pm on Sunday to reports a woman had died.
The teenager is believed to have recently arrived in the UK from India and a 23-year-old man who was known to her has been arrested on suspicion of murder.
A neighbour told the PA news agency the woman “seemed to have a big smile on her face” and looked happy when entering the property at around 3.45pm on Sunday.
Another neighbour said a man was later taken away by police with no shirt on and “looked very passive”.
The neighbour, who did not want to be named, told the PA news agency several families live at the address, adding: “For about two or three months there’s been so many people coming and going.”
Three forensics vans were at the scene on Monday, with a police cordon in place around the property and a van parked on its drive.
A Metropolitan Police spokesman said the woman was found dead at the scene having suffered stab wounds.
The suspect was arrested at the property but was taken to hospital for treatment to a minor head injury.
The woman is believed to be an Indian national who is thought to have arrived in the United Kingdom relatively recently, the spokesperson said.
A post-mortem examination will be arranged in due course and officers are still working to trace and inform her family.
Officers are not seeking anyone else in connection with the investigation.