Cundy also said that the number of dead or missing in the fire has now risen to 79, but that number may change as the investigation continues, he said.
Metropolitan Police Commander Stuart Cundy said the figure included the previous death toll of 30, reports the Independent.
"It's hard to describe the devastation the fire has caused", Candy said.
Flames engulfed the building in less than an hour early on June 14, trapping many residents before firefighters could reach them.
London police on Sunday released images taken within the tower, saying conditions inside verged on the "indescribable".
Some families living in the tower had lost more than one member, he said.
"It is incredibly emotional working in there, but we will do it with our utmost professionalism, and we will do everything we can as quickly as we can to locate and recover everybody who is in there", Cundy said.
On the same morning Cundy delivered his update on the fire, a moment of silence was observed in honor of those it has affected.
Search and recovery crews have been working in the tower since last Wednesday's fire. The job's contractor has said the work met all fire standards.
Two British ministers have said that exterior cladding used in Grenfell Tower's recent renovation may have been banned under United Kingdom building regulations.
The building was previous year fitted with insulating cladding, but the material used is now believed to have been highly flammable and could have further inflamed the fire, helping it spread alarmingly fast throughout the building. Cundy said he would be "looking at all criminal offenses that might have been committed by any individual or any organization". "We will go where the evidence may take us".
While emergency services have been widely praised for their handling of the disaster, the government has been criticised for a slow and inadequate response, with Prime Minister Theresa May facing public anger for failing to meet residents during her first visit to the site.