The figures were confirmed in an update by the Metropolitan Police into the investigation following the disaster in 2017 which killed 72 people.
The police investigation is set to complete by September when files will be handed to the Crown Prosecution Service for charging decisions.
Potential charges include corporate manslaughter, gross negligence manslaughter, misconduct in public office, fraud and health and safety matters.
Deputy Assistant Commissioner Kevin Southworth said: “The Grenfell Tower fire remains one of the most complex investigations ever undertaken by any UK law enforcement agency. Our investigation began in June 2017 and has continued relentlessly since.
“We have been working in close partnership with the CPS for many years already and are on schedule to submit all files this autumn. The CPS will then consider them in detail to make charging decisions and are confident they can do so before the 10th anniversary of the fire.”
The police said 14,400 statements had been taken and more than 27,000 exhibits, including cladding, insulation, doors, windows and other parts of the building, down to screws, nut and bolts, are stored in a warehouse.
