The fire at a block of flats at Green Court, Luton, broke out at 4am on April 21, with eight people, including a police officer, being injured and taken to hospital.
Beds Police say detectives investigating three attempted arson attacks at properties in the area in the early hours of Wednesday morning had identified an occupant of the flats as a suspect through CCTV enquiries.
As part of the ongoing investigation, a team of five officers, from Response and CID, were deployed to a flat on the 14th floor at 4am on Thursday.
However, on arrival officers were confronted with a fire at the entrance to the flat.
The officers tried to gain entry to the property to get the occupant to safety, but were overcome by the fire. One of the officers in particular suffered serious burns and remains in hospital.
A police statement added: “As the fire took further hold of the flat, the occupant fell from the window and sadly died.
"While formal identification is still yet to take place, police have made contact with the next of kin of who officers believe him to be, and specialist officers are supporting his family.
“As with any case which involves serious injury or death following police contact, the matter was immediately referred to the Independent Office for Police Conduct and Bedfordshire Police continues to work with them to ascertain all of the facts.”
Assistant Chief Constable Sharn Basra said: “This is a tragic case and we are working hard to establish all of the facts of what took place. Our focus yesterday was on identifying the man who had died and tracing his family members before we released any further information publicly.
“We have also been carefully recovering all possible evidence from the scene and assisting residents who had been displaced from their homes.
“What is clear from the evidence collected so far is the bravery of the attending officer, who tried to fight through the flames to save the man inside. Our thoughts remain with both him as he recovers in hospital and the loved ones of the man who sadly died.”
Bedfordshire Police confirmed the flats were safe to re-enter from 7.30pm last night except those on the 13th and 14th floor, closest to the fire which broke out.
The majority of those affected were able to return to their homes last night after being looked after by the authorities at a local community centre. (21/4).
A post of the Police Facebook page stated: “We're pleased to confirm that residents will be able to return to their flats between the ground floor and 12th floor.
“The 13th and 14th floors remain closed off at this time and we're working with partners to support those affected.
“There will be an ongoing police presence at the scene.
“We'd like to thank all those who have been displaced for their ongoing patience and appreciate how difficult today has been for them."
Anyone with any information is asked to call 101 or get in touch with police online quoting Operation Cheagle.