The Metropolitan Police have issued an update into the investigation into the tragedy in June 17 which it described as “one of the largest and most complex” ever undertaken by the Met.

A team of 180 officers and staff have identified and are investigating 19 companies or organisations and 58 individuals, as suspects.

Police said they have so far interviewed under caution over 50 suspects for a total of more than 300 hours and have taken more than 12,000 witness statements and retrieved more than 152 million documents and files.

They have also collated more than 27,000 exhibits, which are held in a 635 sq m warehouse big enough to park 25 double decker buses inside. The exhibits include cladding, insulation, doors, windows and other parts of the building, down to screws, nuts and bolts.

The police probe is running alongside the independent public inquiry into the blaze which is expected to publish its final report by this autumn.

The update said it will take the investigation team at least 12-18 months to fully assess the inquiry’s report and complete evidential files to present to the Crown Prosecution Service for charging decisions.

Deputy Assistant Commissioner Stuart Cundy said: “At the heart of the police investigation are the bereaved and survivors, who have gone through so much. I can’t pretend to imagine the impact of such a long police investigation on them.

“This is one of the largest and most complex investigations ever undertaken by the Met, the scale and legal complexity is immense. We have been working since the night of the fire to leave no stone unturned in our investigation into what happened.

“Based on where we are today, we believe it will take us at least until the end of 2025 to fully assess the public inquiry’s phase 2 report and finalise evidential files to present to the CPS for charging decisions. We have updated the bereaved and survivors with our expected timescales and we know how long this sounds, on top of the very long time they have already waited.

“To provide some context, the inquiry’s phase 1 report was more than 800 pages long. We expect the phase 2 report will be substantially longer and much more complex. We must fully assess the findings of the report – line by line – against the evidence we have gathered in our investigation.

“It’s very possible we will then need to explore further evidence and witnesses, and interview some or all of the criminal suspects again.”

Rosemary Ainslie, head of the CPS Special Crime Division, said: “The police anticipate sending complete files of evidence to us by 2026.

“There is great benefit in this case that we have been working closely with police throughout and will therefore be in a strong position to consider the final evidential files when they have been completed.

“However, as you will appreciate, due to the sheer volume of substantial evidence, there is still a lot of work to be done in reaching any charging decisions.

“It is our hope that by the end of 2026, we will be in a position where we are making decisions.

“As you will appreciate it is not possible to provide any timescales on our charging decisions, so we will not be able to give a definitive date on when everything will be completed but our team of specialist prosecutors will need time to review the final file carefully and thoroughly before making their decisions.”