It's one line of inquiry that we are pursuing," says a Scotland Yard spokesperson.
Police discovered three dead bodies in the garden of the home of the former EastEnders actress on January 5. Although the remains have not been identified, it is believed they are those of former EastEnders actress Blake, 43, and her sons Zachary, 8, and Amon, 4, who were reported missing in mid-December.
Photographs obtained by ITV News show Blake's partner, Arthur Simpson-Kent, 48, entering Kotoka International Airport in the Ghanaian capital Accra at just after 9pm on December 19th – three days after he was questioned by British police.
Scotland Yard's murder squad has publicly appealed for "any information" that could help trace Simpson-Kent – a hair stylist who claims to have worked in TV and magazines alongside fashion houses Versace, Armani and Givenchy.
Blake played soul singer Frankie Perrie in hit BBC soap opera Eastenders for 56 episodes in the 1990's. She went onto appear in a number of other British soaps including The Bill, Casualty and Skins before moving into theater and later becoming a sign-language tutor.
More recently, she was diagnosed with motor neurone disease, the same degenerative brain and spinal chord condition that Professor Stephen Hawking also suffers from.
Neighbor Sandra Metzgen described Blake to The Times as being "very frail" before she vanished, adding that "she sounded like she didn't have very long left."
Sian's Sister: 'I Want Him to Be Brought Back to Justice'In an interview with ITV, Ava Blake, Sian's sister, said, "Unfortunately, I believe Arthur was responsible."
She said, "I want him to face justice and explain why." She added, "He'll have to answer to the courts of this country and to God eventually."
She said 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. Blake and her sons were last seen on December 13, and despite the fact that the family home in Erith, Kent was searched shortly afterwards, the three bodies were not discovered in the rear garden until 20 days later.
The Metropolitan Police has since voluntarily referred the investigation to the Independent Police Complaints Commission after a review highlighted "potential issues."
"The timeline as to what activity police did when and how will be subject to the investigation," the Scotland Yard spokesperson adds.
"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.
The spokesperson continues, "It is an ongoing murder investigation led by the Homicide and Major Crime command.
"It is very fast moving and there are a number of lines of inquiry."