Speaking outside Scotland Yard, Mr Cundy added: "I have investigated major crime for most of my service and I have seen some bad things".
He promised an "exhaustive" criminal investigation that would also look at a major refurbishment of the tower completed a year ago. "This is an incredibly distressing time for all of them".
"My understanding is that the cladding that was reported wasn't in accordance with United Kingdom building regulations", Hands told Sky News.
Detectives investigating the Grenfell Tower fire said the official number of presumed dead "will be higher" than the current figure of 58 as they released new images showing the scale of devastation inside the building.
The government is carrying out an "urgent inspection" of roughly 2,500 similar tower blocks across the country to assess their safety.
"The key question now is whether the overall design of the building's complete exterior was properly tested and subsequently signed off by the relevant authorities including the fire officer, building compliance officer and architect before commencement of the project".
Three more victims killed in the Grenfell Tower disaster have been named, after Scotland Yard announced the death toll had risen to 79.
Cundy said it was hard to describe what he saw when he went into the building on Saturday. "We need to find out precisely what cladding was used and how it was attached".
Hands cautioned Sunday that investigators still don't know exactly what cladding was used when the building renovation was completed previous year.
Police Commander Stuart Cundy says police will seek criminal prosecutions if the evidence warrants.
Labour Party leader Jeremy Corbyn said Sunday the government has the power to take over empty apartments and offer them to the hundreds of Grenfell Tower residents left homeless in Wednesday' inferno.
British Prime Minister Theresa May herself had come in for a barrage of criticism over her own response to the disaster. Five people who died in the blaze have been identified and 74 were missing and presumed dead following the devastating blaze in the council-owned Grenfell tower block in west London.
In addition, British health authorities will provide long-term bereavement counseling for those who lost loved ones in the tragedy.