The death toll from the Grenfell Tower fire is believed to be around 80 people, the vast majority of whom were from just 23 flats, police believe.
Metropolitan Police Detective Superintendent Fiona McCormack said contact had been made with at least one occupant from 106 of the 129 flats in the building.
From those properties, 18 people are dead or assumed dead, meaning the remaining victims are thought to have been in the flats wiped out by the inferno.
It will be months before the final roll call of victims is established, Ms McCormack said.
She said: "There are 23 flats that despite huge investigative efforts, we have been unable to trace anyone that lives there.
"At this stage we must presume that no-one in those flats survived, that includes anyone who lived there or was visiting them."
Pressed on whether the death toll could climb to triple figures, Ms McCormack said: "I've said I believe it could increase, I don't think it's going to be triple, no."
A six-month-old baby was among the latest victims to be identified, found dead in her mother's arms in the smoke-filled stairwell.
Westminster Coroner's Court opened and adjourned inquests into seven Grenfell Tower victims, including baby Leena Belkadi and her eight-year-old sister Malak.
As the vast criminal investigation into the fire continues, 60 organisations have been identified as having a hand in the tower's refurbishment, which is suspected to have aided the spread of the blaze.
Prime Minister Theresa May confirmed on Wednesday that 120 tower blocks across 37 local authority areas have flammable cladding on their exterior.
Efforts to establish who was missing in the wake of the fire were focused on talking to friends, families and neighbours of those in Grenfell Tower, Ms McCormack said.
A list of tenants provided to police by the Kensington and Chelsea Tenants Management Organisation, which managed the building, was "not accurate", she claimed.
"We are many months from being able to provide a number which we believe accurately represents the total loss of life inside Grenfell Tower.
"Only after we have completed a search and recovery operation, which will take until the end of the year.
"What I can say is that we believe that around 80 people are either dead or sadly missing and I must presume that they are dead."
The 23 flats which were said to have no survivors were spread between the 11th floor and the 23rd.
Around 10 flats remain too perilous for police to venture into for thorough examination.
Amid mounting distrust of the official death toll, Ms McCormack stressed "every imaginable source" of information about who was in the building had been examined, "from government agencies to fast food companies".
She said: "What we know is that it would be impossible for anyone to produce a list to show exactly who was at Grenfell Tower that night, that includes the people who were living there or who were visiting."
A couple who were missing and assumed dead had actually been on holiday at the time of the blaze, according to the detective.
Referring to the criminal probe, which has set out to establish if charges including manslaughter will be brought, Ms McCormack said: "We are continuing to seize material on a daily basis and the number of companies and organisations that we know so far had played a role in the refurbishment is over 60."
This number is expected to rise, she said, adding: "So far everybody has been compliant and we've actually been provided with a wealth of documents already."
Despite the painstaking recovery process, optimism that remains of all victims would be recovered from the building is beginning to ebb away.
"We are working very hard to identity everyone who died in the fire, but the tragic reality is that due to the intense heat of the fire, there are some people we may never identify.
"Tragically, we are preparing families and loved ones for the fact we may never recover the remains of their loved ones."
A renewed call was made to groups with lists of suspected victims and those who were living in the building illegally to come forward.
Ms McCormack said: "Our aim is the same - we want to understand the true human cost of this tragedy."