A woman has been charged with the murder of her baby son and daughter.
The 10-week-old boy and his 14-month-old sister, Lily Sky Boots, were found unconscious on Wednesday evening by their father, Jeff Boots, when he returned from work to his home in Wandsworth, south-west London, sources said.
Metropolitan Police officers arrested their mother, Felicia, 34, at the semi-detached home after emergency services were unable to revive the children at the scene.
Scotland Yard said a 34-year-old woman had been charged with two counts of murder and would appear at South Western Magistrates Court in south London.
A police spokesman said: "A 34-year-old woman has been charged with two counts of murder following the discovery of the bodies of a 14-month-old girl and a 10-week-old boy at an address in Killarney Road on Wednesday May 9."
Further tests had been carried out after a pathologist could find no formal cause of death for the two children, police said.
Post-mortem examinations took place on Friday at Great Ormond Street Hospital in London but a cause of death had not been given.
The bodies of the children were discovered at the upmarket property which the family moved into. It had recently been sold by Savills estate agency for £1.2 million.
Mrs Boots, a trained hairdresser, had been busy completing removal from a nearby penthouse apartment in the weeks before the deaths.
Both Mr Boots, an investment banker, and his wife are understood to have moved to the UK in the last few years from Canada.