This tragic image shows what appears to be Sian Blake's murdered son in his bedroom just weeks before he died with his mother and brother.
The image - found on Google Street View - shows what neighbours believe is Zachary at the front window of his home in Erith, Kent.
Taken in September 2015, the picture shows the child wearing a red jumper and looking around what is believed to be the room's curtains.
Zachary, his four-year-old brother Amon and his mother Ms Blake, 43, a former EastEnders actress, were reported missing just before Christmas.
They were found and buried in the back garden of their home earlier this week.
They were last seen when they visited family in Leyton, East London, on December 13.
A post mortem examination revealed they all died from head and neck injuries.
Miss Blake's boyfriend Arthur Simpson-Kent, 48, was yesterday pictured arriving in Ghana as it emerged that Ms Blake's family had accused him of domestic violence in the weeks leading up to the killings.
Neighbours living opposite the bungalow have said they often saw the children waving to them from their bedroom window - the front room of the house where Zachary can be seen in this picture.
One neighbour who did not want to be identified, said: "You can see an image of Zachary looking out of his bedroom window on Street View. His face is blurred in it but it is so sad to see.
"Zachary and his brother Amon would often look out of the window and wave to us.
"It's so tragic. It breaks my heart.'
Neighbour Sandra Metzgen, 44, said: "The kids used to wave to me from the window to their room.
"They were always in the house and never came out."
It is understood concerns about domestic violence were raised by a relative of Ms Blake to the NSPCC on December 16.
A missing person's investigation started on the same day after police attended the family home in Erith, Kent.
On Tuesday - almost three weeks later - three bodies were discovered in the garden of the property, triggering a murder inquiry.
ITV News obtained photographs of Simpson-Kent, 48, at Kotoka Airport in the Ghanaian capital Accra - three days after he was quizzed by police over the family's disappearance.
Yesterday Ms Blake's sister Ava said the killer will have to "answer to God", revealing that her sibling had told their mother, Pansy, that she wanted to get out of her relationship "a long time ago".
Ms Blake, 43, had motor neurone disease - a fatal, rapidly progressing illness which affects the brain and spinal cord - and was reportedly looking "very frail" before she vanished.
IPCC Associate Commissioner Tom Milsom said: "The loss of Sian and her two young boys Zachary and Amon, is a tragedy and my thoughts are with their family during this very difficult time.
"The IPCC will be conducting a thorough investigation into how police responded to the concerns for their welfare and their disappearance."
- Daily Mail