Stay-put advice given to residents in Grenfell Tower will form part of the police investigation into the fire, Scotland Yard said.
Detective Superintendent Matt Bonner said the actions of London Fire Brigade (LFB) would be examined to see if health and safety laws were broken.
Fire commanders responding to the inferno have been criticised for taking nearly two hours to order a full evacuation of the block, despite flames reaching every floor.
Both the LFB and the Fire Brigades Union defended the decision at the public inquiry into the disaster on Thursday, suggesting there had been “no obvious and safe alternative strategy”.
Mr Bonner told a separate briefing: “The LFB would, as any other organisation involved, have an obligation to conduct their activity in a manner that doesn’t place people at risk. It doesn’t mean that at the moment they have or they haven’t, but that’s where the legislation is most likely to arise if that was an eventuality.”
The stay-put policy was “part of our assessment of what happened and therefore falls within the investigation”, Mr Bonner added.
Commander Stuart Cundy said force was “duty bound” to look at a broad range of aspects from the night, which included the emergency services’ response and preparedness.
The development came as the FBU warned Sir Martin Moore-Bick not to allow criticism of firefighters’ decision-making to be “exploited by those who created the danger”.
Martin Seaward, representing the union, said the inquiry’s investigation should avoid being swayed by the “benefit of hindsight”.
On the final day of opening statements at the probe, it was said both commanders and firefighters faced an “impossible situation” on June 14.
A botched refurbishment had turned the block into a “highly combustible death trap”, which the brigade lacked training and procedures to tackle, Mr Seaward said.
The lawyer told the inquiry there was “no evidence” any firefighters “were aware of the state of the building”.
He said: “Any criticisms of the emergency response should be assessed against this background and should not be exploited by those who created the danger. We ask the inquiry to maintain this sense of perspective.”
Fire safety advice within tall buildings is set by the building owners, not the fire service, meaning it accords with the design specifications and escape capabilities.
It is feared, however, that the decision to keep the stay-put advice in place until 2.47am might have cost lives.
Stephen Walsh QC, representing the LFB, told the inquiry: “It is a fundamental misunderstanding of the events of the fire and of fire service capability to assume the building’s stay-put policy can be changed to a simultaneous evacuation at the stroke of a fire incident commander at whatever time.
“If there is no policy applied by the building owner which provides for a policy of simultaneous evacuation and there are no evacuation plans and there are no general fire alarms – what is an incident commander on the fireground to do?”
Mr Seaward likewise asked “what alternative strategy might have been implemented” in the fast-moving situation.
He said: “There remains no obvious and safe alternative strategy nor detailed plan.”
Both call operators and firefighters on the scene still suffer from the physical and emotional repercussions of responding to the disaster.
The inquiry was told how LFB’s command centre was swamped with more calls seeking survival guidance than in the previous 10 years for the whole of London combined.
Fifty-two firefighters are expected to give evidence at the probe, leading the LFB lawyer to remind chairman Sir Martin of their potentially fragile state of mind.
Mr Walsh said: “Their collective and individual instinct is and was on the night to protect life and property, often at great risk to their own safety, resulting in physical and mental injury for many.”
The judge was also advised by the FBU to consider whether early incident commanders had training and procedures on issues such as tackling cladding fires, looking out for signs of a breach of compartmentation and when to abandon a stay-put policy.
The openings concluded at Holborn Bars in central London on Thursday.