Two further people have been arrested on suspicion of murder after a man died in a fire at a former care home.
Patryk Mortimer was found unconscious in a building that previously housed Manor House Care Home, in Easington Lane, Sunderland.
The 39-year-old died later in hospital. Nine other people were brought out of the property by firefighters.
A 21-year-old man and a 36-year-old woman have now been arrested and are in police custody.
Two men, aged 23 and 35, who were arrested on suspicion of murder on 4 November, the day after the fire, have been released while investigations continue.
Northumbria Police said more than 400 hours of CCTV footage had been seized as part of the inquiry.