Murder squad detectives are searching for the boyfriend of an ex-EastEnders actress after three bodies were found by police looking for the performer and her two children.
Shocked neighbours of Sian Blake, 43, who played Frankie Pierre in the hit soap, broke down in tears after the discovery in the garden of her home in Erith, Kent, on Tuesday.
She vanished with her sons Zachary, eight, and Amon, four, in east London on December 13, and Scotland Yard is facing questions over why it took three weeks for a homicide team to be called in and the bodies found. The force's professional standards team is looking at the way the investigation was handled.
Three days after Ms Blake and her sons disappeared, police interviewed her partner, the children's father Arthur Simpson-Kent, 48, at the family home, before he also vanished.
Detective Superintendent Paul Monk said: "Sadly we found three bodies in the back garden of their home address and as such, this is now a murder investigation.
"Formal identification has yet to take place, it's too early to speculate but of course the family has been told and this is obviously a very difficult time for them.
"Our efforts are continuing to find Arthur Simpson-Kent. Our appeal is to anyone who may know his current whereabouts or can assist us in finding him - we do need to speak to him as a matter of urgency."
Post-mortem examinations will be carried out on Wednesday on the bodies, which have yet to be formally identified.
Next-door neighbour Sam Sanni-Alashe was in tears over the discovery. He said: "I am in shock, I can't talk. It is really hurtful. I know the lady. I see the children playing at the back. I say hello all the time. We are not close but she was a very happy woman.
"This is a disaster and it is awful for the community. I can see everything in the garden but these last few days I have chosen not to look. When my son finds out, he will be terrified."
Ms Blake had motor neurone disease - a fatal, rapidly progressing disease that affects the brain and spinal cord - and was reportedly looking "very frail" before she vanished.
She and her children were last seen in Waltham Forest, east London, on December 13, and her silver-beige Renault Scenic was found in Calvert Avenue in Bethnal Green, east London, on January 3, but it is not known who parked it there.
Another neighbour, Hannah Cutting, 18, said: "I would see the kids playing at the window, then we were worried when police were there 24/7.
"It's awful just to think that something can happen on your doorstep and you see people and you have no idea what's going on."
A 30-year-old woman living nearby who knew Ms Blake tearfully said: "She was a lovely, caring lady and we didn't know anything about her being in EastEnders. She was just the sign-language tutor with her two boys.
"I just feel really upset because I imagine that house and I just see those boys playing about and getting in the car. I was hoping she was just hiding away to have her last Christmas.
"I knew she was ill but we didn't know with what. I wish I had been a better neighbour. I'm devastated."
A family member reported Ms Blake and her children missing on December 16, and two days later a missing persons inquiry was launched, but not classed as high risk.
The same day, December 18, officers went back to the Erith home, and forced their way in when there was no answer at the property. Scotland Yard could not provide details of how many other times police had searched or visited the house.
The investigation was classed as high risk at some point after Christmas, and on Monday the murder squad took over the inquiry and the Met's professional standards team was brought in.
A Scotland Yard spokesman said: "The Directorate of Professional Standards was informed on January 4 and is working with the investigation team to fully understand the timeline of police interaction with the family."
Previously an unknown actress, Ms Blake's big break came when she was introduced as soul singer Frankie in EastEnders in June 1996 by series producer Jane Harris.
Her storylines saw her character frequently pursuing attached men and breaking up the marriage of Alan and Carol Jackson, played by Howard Antony and Lindsey Coulson.
According to IMDB, Ms Blake was on the show for 56 episodes, reportedly quitting in 1997 because of hostility from viewers towards her manipulative character.
Her contemporaries on the BBC soap included Patsy Palmer and Dean Gaffney - who played Alan's stepchildren Bianca and Robbie - as well as Michael French (David Wicks) and Sylvester Williams (Mick McFarlane).
Ms Blake also appeared in episodes of The Bill, Casualty, Doctors and Skins, and was the voice of Yugiri in 2015 video game Final Fantasy XIV: Heavensward.