Up to 57 individuals and 20 companies could face criminal charges over the Grenfell Tower fire disaster, the Metropolitan Police has said.
Potential offences under consideration include corporate gross negligence manslaughter, fraud, health and safety breaches and misconduct in public office.
In an update at New Scotland Yard, the force said it would submit evidence files to the Crown Prosecution Service (CPS) by the end of September this year.
A final decision on whether to bring charges could take until June 2027 - 10 years after the fire in west London, which killed 72 people. If the CPS does decide to prosecute, any trials are unlikely to begin before 2029.
A spokesman for Grenfell United, which represents some of the bereaved families and survivors, said the development was "an important step in a process that has already taken far too long".
The Grenfell Tower fire was caused by a chain of failures by governments, "dishonest" companies and shortcomings in the fire service, a public inquiry found.
Operation Northleigh, the £150m probe into the disaster of 14 June 2017, has examined the actions of 15,000 people across 700 organisations in the largest and most complex investigation ever carried out by the Met Police.
Jackie Leger and Bernie Bernard, the sisters of Raymond "Moses" Bernard, who died in the fire, said they hoped to see charges brought against "those complicit in the deaths of the 72 victims".
Bernard told the BBC: "The decision makers need to be brought to justice, not middle management, not lower management, but the people that made the decisions need to take responsibility for what happened at Grenfell".
Grenfell Unite also said those responsible must be held to account and called for no further delay to proceedings.
The group said: "For our community, this is not news we meet with celebration. We meet it with caution, grief and determination. We have waited almost a decade for accountability."
It added that the Ministry of Justice and the government must ensure the courts were properly resourced so any prosecutions linked to Grenfell could be heard swiftly.
Organisation Grenfell Next of Kin responded to the news saying it was of "little comfort to us".
"There is a complete breakdown in trust and confidence. We no longer have faith in the institutions responsible for delivering accountability. After years of delays, reassurances and procedural updates, confidence in the system has been shattered.
"The criminal investigation and justice process should always have come first and been given priority. Instead, the £172m Public Inquiry was prioritised ahead of criminal accountability and delayed our justice.
"Once again, everything connected to Grenfell has been handled upside down and the wrong way round. The first step towards justice for us is answering the fundamental question of why and how our justice was delayed and denied in the first place."
The CPS has already begun reviewing some of the evidence.
Garry Moncrieff, from the Metropolitan Police, said the final number of people and organisations being considered for charge was "not expected to vary a lot" when the full submissions were made in September.
He said officers had gathered extensive material over several years as part of the inquiry.
"We have gathered strong evidence," Moncrieff told reporters at a Scotland Yard briefing.
He added: "It is important that we do it once and do it right."
The Met Police chose to wait for the findings of the Grenfell Tower fire public inquiry before looking into the potential for criminal charges.
The inquiry began in 2017 and concluded in 2024. Moncrieff said this had added time to the investigation but had not damaged it.
Speaking to BBC Radio 4's World At One, Michael Mansfield KC, a barrister representing some of the victims, criticised the approach to delay seeking charges until after the public inquiry's completion.
Mansfield said: "There was an opportunity to have not delayed this long if the police investigation had started at the time the inquiry did."
The Met said clarified that its investigation began on the day of the fire and did not wait for the public inquiry to begin, but said it did wait until the inquiry had published its final report so it could consider this evidence.
He added that the decision to wait for it to conclude "tacks on five or six years or more", describing it as "an unwarranted delay".
Mansfield said the problem was with "the system we have in place" following a disaster.
"You have to rethink that situation because in future it's going to happen again and justice will be put off for this length of time."
Moncrieff would not be drawn on how likely it is that charges will be brought, but said investigators were building full-scale replica sections of the tower at a cost of £2m in preparation for possible court proceedings.
He said forensic teams spent 14 months at the site gathering evidence and had since examined material linked to hundreds of companies and thousands of individuals, as well as evidence from the public inquiry.
Police said 165 million electronic files had been gathered and searched, while 14,400 witness statements have been taken.
So far, 15 of the 20 case files have been passed to the CPS for advice.
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