Police were called on Tuesday 1st January to a flat above the Black Horse in Longbrook Street
The death is not being treated as suspicious.
The woman's family has been told.
Detective Inspector Glenn Willcocks, said: “Scenes of crime officers have been carrying out their investigation at the address in Culver Road since the discovery of a body following a fire at the property on Sunday.
“Initial forensics and crime scene investigations have now taken place as well as an initial post-mortem on the deceased. On the back of this, it is our current belief that the woman died of smoke inhalation.
“The investigation has not identified anything suspicious. The death remains unexplained and we await further results in due course from toxicology.
“This house will now be secured and the police cordon removed. The formal identification process is yet to have taken place and enquiries continue into this matter.”