UPDATE
Police confirmed on Thursday night that the three bodies found in Sian Blake's garden on Tuesday are those of the former EastEnders actress and her two sons.
The Metropolitan police said in a statement that post-mortems had given a provisional cause of death of head and neck injuries.
Former EastEnders actor Sian Blake, who went missing before Christmas with her two young sons, was planning to leave her "controlling" partner, who is now thought to have fled the country, her sister revealed on Thursday.
Ava Blake, 51, said Sian's partner, Arthur Simpson-Kent, 48, was a "controlling" boyfriend who monitored her sister's phone calls.
She said Sian had said she wanted to get out of her relationship "a long time ago" and that their "relationship had come to an end", the Press Association reported.
Sian Blake, 43, and her two children, Zachary and Amon, aged 8 and 4, were declared missing on 16 December. Police forensic investigators found three bodies in the garden of the family's home in Erith, southeast London, on Tuesday.
Simpson-Kent was also declared missing after police officers visited him at home on 16 December.
Several reports have placed Simpson-Kent in Ghana, and on Thursday ITV News claimed to have obtained a picture of him arriving in the country's Kotoka International Airport three days after being questioned by police.
Scotland Yard would not comment on Simpson-Kent's whereabouts.
In an emotional interview, Ava said that in the last year her sister had been "more quiet" and "not the vivacious, happy person she once was".
The family had planned for her to move out of the house she shared with Simpson-Kent.
"She had asked to come back home and we said yes, so we really tried to plan on getting her to move back home," Ava said.
"In our opinion the relationship had already come to an end but she hadn't quite made that break or that decision to leave Arthur.
"She may not have told him. She also wanted to do it in a way that caused the minimum amount of discomfort to him as well.
"She didn't want to throw him out on the street but give him time to find somewhere else to live. That was the only point she was wavering on."
Blake and her two children were last seen visiting family in Leyton, east London, on 13 December.
She was known to suffer from motor neurone disease and was said by neighbours to have looked "very frail" before her disappearance.
Met police officers spoke to Simpson-Kent at the family home in Pembroke Road, Erith, but he has not been seen since.
Her silver-beige Renault Scenic was found in Calvert Avenue in Bethnal Green, east London, on Sunday 3 January. It is not known who parked it there.
Tributes and messages have been left at the family home in Erith.
Questions remain over why it took three weeks from the missing person inquiry being launched for three bodies to be discovered in the family's garden.
The Independent Police Complaints Commission (IPCC) is now investigating the handling of the missing persons inquiry, in terms of its speed and urgency, after the Met voluntarily referred the case.
The missing persons inquiry was originally being handled by local police in Bexley before the case was taken over by Met homicide detectives on 4 January.
The Met's directorate of professional standards is still trying to "fully understand the timeline of police interaction with the family".
However, Blake's sister said she was satisfied with the police's response so far.