Postmortem examinations have provisionally concluded that the former actress, 43, and her children died as a result of serious head and neck injuries.
Further forensic tests are being carried out and family members being comforted by specially trained family liaison officers, authorities say.
In a written statement, Detective Superintendent Paul Monk from Scotland Yard's Homicide and Major Crime Command (HMCC) made a further appeal for "any information" that might lead to the whereabouts of Blake's boyfriend, Arthur Simpson-Kent, 48.
"We are continuing to appeal for any information about the movements of Arthur Simpson-Kent who was last seen by police officers at his home in Erith on 16 December," says Monk.
"This is a fast moving investigation and we are actively pursuing a number of lines of enquiry. If anyone has any information that they think might help our investigation then I would urge them to get in contact with us."
The Scotland Yard release adds that the police are aware that Simpson-Kent has traveled abroad and that "this continues to be one line of investigation."
Anti-Child Abuse Charity Expressed Concern About Blake's Boyfriend, Simpson-KentThe bodies of Blake and her children were first discovered in the garden of their home address in Erith on Tuesday.
The alarm was initially raised by the NSPCC anti-child abuse charity, who contacted London's Metropolitan Police with their concerns about Blake and her children on Dec. 16.
Metropolitan Police / PA Wire via ZUMA Press
On Sunday the family home was searched by specialist forensic teams and police dogs, which indicated areas of interest within the rear garden. Police later excavated the garden leading to the discovery of the bodies
Metropolitan Police / PA Wire / ZUMA
She added, "He'll have to answer to the courts of this country and to God eventually."
Ava Blake added that her family members "are angry about Sian, but the boys have devastated us. We have lost a generation. We can never replace them."
An Investigation Under ScrutinyThe police investigation into the bodies has come under scrutiny. Even though Blake and her sons were last seen on Dec. 13, after which the home was searched, the three bodies were not discovered in the rear garden until 20 days later.
"The timeline as to what activity police did when and how will be subject to the investigation," the Scotland Yard spokesperson adds.
The spokesperson added, "What we did say on the discovery of the bodies is that considerable efforts had been made to conceal the bodies, and that police had to excavate the garden."