Shortly after 8am on Saturday emergency services were called to the flat at Warley House on Mitchison Road after a fire had been reported by neighbours.
Four fire crews rushed to the Islington property following reports of smoke issuing from the property. Fire crews entered the property and found the unaccounted but sadly they had passed away.
A cordon remain in place around the property.
The fire was confined to the flat and the occupants of neighbouring flats were safely evacuated, according to police.
A joint investigation has been launched into the cause of the blaze by the London Fire Brigade and the Met Police
Both the Met Police and the LFB have been approached for comment