Greater Manchester Police has referred itself to the police watchdog over the death of a 42-year-old woman.
Officers had earlier spoke to the woman, who had minor facial injuries, when they attended an address in Failsworth, Oldham, after they received an abandoned emergency call.
A 57-year-old man was arrested at the scene at about 11.15pm on Saturday and was taken into custody for questioning.
Police later returned to the property in Oldham Road to take a statement from the woman but found her body inside.
A post-mortem examination will be conducted but it is thought there no are suspicious circumstances.
An automatic referral has been made by Greater Manchester Police to the Independent Police Complaints Commission (IPCC).
Detective Chief Inspector Howard Millington said: "First and foremost I would like to express our most sincere condolences to the woman's family for their tragic loss.
"Our thoughts remain with them at this terrible time in their lives and we currently have specially trained officers providing them with support.
"In line with our usual policy when an incident such as this occurs, we have made referral to the IPCC and we await their decision on whether or not they wish to investigate.
"In the meantime, we are continuing to investigating the circumstances surrounding the initial call that was made to police which prompted officers to attend and arrest a 57-year-old man on suspicion of assault."
Anybody with information should contact police on 101, quoting incident number 2778 of 28/05/16, or the independent charity Crimestoppers, anonymously, on 0800 555 111.