A body found in a burnt-out car is that of a woman, police have confirmed.
West Midlands Police said a 34-year-old man arrested on suspicion of murder is continuing to be questioned.
Officers made the discovery after being called to reports of a car fire in Fentham Road in the Erdington area of Birmingham at around 8.30pm on Tuesday.
Post-mortem tests are due to take place later today.
The victim is yet to be identified.
Detective Inspector Warren Hines, of West Midlands Police CID, said yesterday: "We are in the very early stages of what is likely to be a very complex investigation into an exceptionally unusual crime.
"An arrest has been made and we are not looking for anyone else in connection with this matter.
"Officers and staff from a range of departments across the force are working hard to establish what has happened, but I am asking that anyone with information which may help gets in touch as a matter of urgency."
Anyone with relevant information is urged to call police on 101.