Police have warned they may never be able to identify all of the people who died in the fire that engulfed a west London block of flats.
Emergency services are to spend a third day searching for bodies in the burnt-out Grenfell Tower in North Kensington.
Seventeen people are known to have died but that figure is set to rise, with fears the death toll could exceed 60.
Fire chiefs say they do not expect to find more survivors, while PM Theresa May has ordered a full public inquiry.
Police said on Thursday that they had launched a criminal investigation into the fire.
The prime minister – who faced criticism for not meeting survivors of the tragedy on a visit to the scene on Thursday – said the victims “deserve answers”.
Emergency services were called to the 24-storey residential tower block shortly before 01:00 BST on Wednesday.
Six victims of the blaze have been provisionally identified.
However, Metropolitan Police Commander Stuart Cundy said there was “a risk that sadly we may not be able to identify everybody”.
Asked about the number of dead, he said he hoped the death toll would not reach “triple figures”.
He added: “We as the police, we investigate criminal offences – I am not sitting here and saying there are criminal offences that have been committed, that’s why you do an investigation, to establish it.”
The leader of Kensington and Chelsea Council – the authority that owns the tower block – told BBC Two’s Newsnight it would not use the type of cladding fitted to Grenfell Tower in other buildings in the borough.
The cladding – installed on the tower in a recent renovation – has come under scrutiny, with experts saying a more fire resistant type could have been used.
Councillor Nicholas Paget-Brown also said there had not been a “collective view” among residents in favour of installing sprinklers during the renovations.
He said it would have “delayed and made the refurbishment of the block more disruptive”.
Meanwhile, Conservative MP Chris Philp told the programme the public inquiry should produce interim findings to ensure swift action can be taken if residents in other tower blocks are at risk.
“If there are other buildings which have that dangerous cladding then immediate action needs to be taken in a matter of weeks, or months – not in a couple of years,” he added.