A 25-year-old man has been arrested on suspicion of the murder of a woman and her baby son at her home in south London almost a fortnight ago.
Kelly Mary Fauvrelle, and her son Riley, died after she was stabbed at her home in south London.
The 26-year-old Royal Mail worker was eight months' pregnant when she was killed in the bedroom of her home on Raymead Avenue, Thornton Heath, London, in the early hours of 29 June.
Her baby son - who was named Riley by family members after he was delivered by paramedics - died in hospital on 3 July.
A Metropolitan Police statement said: "On Thursday 11 July detectives investigating the murder of Kelly Mary Fauvrelle and her baby son, Riley, arrested a 25-year-old male on suspicion of murder.
"The male has been taken to a central London police station where he remains at this time. Inquiries continue."
The attack took place in Ms Fauvrelle's bedroom while her whole family was at home and relatives heard her screams at around 3.30am.
Two men have been arrested on suspicion of murder previously.
One, aged 37, was released with no further action, and a second, aged 29, has been released on bail until early August.