A man has been arrested on suspicion of the murders of a pregnant woman and her baby son who died days after being delivered.
Kelly Mary Fauvrelle, 26, who was eight months pregnant, was stabbed to death in her home in Croydon on 29 June.
Her son Riley was delivered by paramedics but died on 3 July.
The Metropolitan Police said a 25-year-old man had been arrested and was being held at a central London police station.
He is the third man to be arrested on suspicion of the murders.
A 37-year-old was released with no further action while a 29-year-old was bailed until a date in August.
Police were called by the London Ambulance Service at 03:30 BST to Raymead Avenue, Thornton Heath, where Ms Fauvrelle was in cardiac arrest.
Despite the efforts of paramedics, she died at the scene.
Ms Fauvrelle’s family – including her mother, two brothers, sister and sister’s baby son – were all at the home at the time of the attack and were woken by her screams. However, none of them saw her attacker.
Her son was delivered at the scene but died in hospital.