Police have arrested a man on suspicion of murder in Cheltenham in the early hours of Saturday 31 August.
Emergency services were called to a report of a woman who had been seriously injured at a property on Fairfield Road at around 3.30am.
A 66-year-old woman was declared dead at the scene.
A man, aged 77 and from Cheltenham, has been arrested and remains in police custody while enquiries continue.
There is currently a scene guard in place at a property while police remain at the address.
Officers from the Major Crime Investigation Team are in the early stages of an investigation and are appealing for anyone who has any information to come forward.
Information can be provided to police online by completing the following form and quoting incident 42 of 31 August: www.gloucestershire.police.uk/tua/tell-us-about/cor/tell-us-about-existing-case-report/
Alternatively you can report information anonymously through the independent crime-fighting charity Crimestoppers by calling 0800 555 111 or visiting their website: https://crimestoppers-uk.org/give-information/forms/give-information-anonymously anonymously