Police have named the man who died in the house fire in Midland Road, Wellingborough, last week.
He has been formally identified as 48-year-old Steven Chennell of Wellingborough.
Det Chief Insp Martin Kinchin said: “Steven was a man with his own property and was in very regular contact with his local family but, in recent years, had chosen to live rough in Wellingborough.
“This lifestyle means there are limited recent photographs of Steven and his family would prefer to remember him as the smart, younger man he was previously.”
Mr Chennell’s family paid tribute to him, saying: “Steve will be dearly missed. He was a much-loved member of our family and touched the heart of everyone he met.”
DCI Kinchin added: “Steven was quite well known in the town and we are keen to talk to anybody who saw him on Tuesday, March 4.
“Anyone with information should call Northamptonshire Police on 101. Alternatively, they can call Crimestoppers anonymously on 0800 555 111.”
A 36-year-old Wellingborough man, arrested in connection with the fire, has been released on police bail pending the results of forensic investigations and their consideration by the Crown Prosecution Service.
However, police have confirmed their investigation centres around the circumstances of the fire starting and they are not looking for anybody else.