Police will need until the end of 2025 to finalise their investigation into the Grenfell fire, with final decisions on potential criminal charges by the end of 2026.
Metropolitan Police Deputy Assistant Commissioner Stuart Cundy told journalists that investigators will need another year to 18 months after the publication of the report from the second part of the public inquiry into the blaze, due to be released later this year.
Rosemary Ainslie, from the Crown Prosecution Service (CPS), said prosecutors would then need until the end of 2026 to make final decisions about any criminal charges.
The mammoth police investigation into the fire, which killed 72 people in 2017, has already generated 27,000 lines of inquiry and more than 12,000 witness statements.
A total of 19 companies and organisations are under investigation for potential criminal offences, and 58 individuals, and more than 300 hours of interviews have taken place.
Potential offences under consideration include corporate manslaughter, gross negligence manslaughter, perverting the course of justice, misconduct in public office, health and safety offences, fraud, and offences under the fire safety and building regulations.
So far eight out of 20 files have been sent to the CPS for early investigative advice that would be passed back to police, with a typical case file more than 500 pages long with 17,000 pages of evidence.
The current timeline would mean it would be nearly 10 years before anyone could appear in court over the Grenfell Tower blaze.
Up to the end of March this year, the Met has spent £107.3 million on the inquiry, and there are 180 investigators currently working on the case.
Metropolitan Police Deputy Assistant Commissioner Stuart Cundy said the publication of the report will be a landmark moment for the police and those directly affected by the fire.
He said: “Based on where we are now, our estimation is that it will take at least another 12 to 18 months, once the inquiry publishes its report, before we will be in a position to finalise in essence what many people would call the charging file for us to then pass across to… the specialist lawyers within the Crown Prosecution Service.
“I know that sounds such a long period of time.
“Seven years ago, we made a commitment to the bereaved and the survivors that we would follow the evidence wherever it would take us, we remain true to our word with that.
“We as the police have one chance to get this investigation done to the right standard, the right quality, and done the right way.
“We owe that to those who lost their lives, owe it to everybody who has been affected by the Grenfell Tower tragedy.”
Ms Ainslie said: “Due to the sheer size and volume of the completed evidential files, we will need to take the necessary time to properly evaluate the evidence and to provide final charging decisions.
“It’s not possible to be definitive about timescales, but it would be our hope that by the end of 2026 we will be in a position where we are making final charges.”
In a briefing with journalists at New Scotland Yard on Wednesday, Senior investigating officer Detective Superintendent Garry Moncrieff said officers will have to go through the public inquiry report line-by-line to measure any impact on their investigation.
He acknowledged that the police inquiry is taking a long time but said it is “a really complex” investigation.
Officers have retrieved more than 152 million files, gathered 75,000 photos and 27,000 exhibits.
Forensic teams spent 415 days examining the tower itself after the deadly blaze and painstakingly gathering evidence.
Exhibits are being stored in an enormous warehouse that is big enough to store 25 double decker buses.
It includes the charred remnants of cladding panels that would have had molten plastic dripping down them while the building was on fire.