Adam Harris from Dukinfield had been arrested and taken to Ashton under Lyne police station after officers were called to West Street to reports of fighting around 1am this morning.
Harris fell ill about three hours after his arrest and was taken to hospital where he sadly died.
Further enquiries established that a second man was involved in the original altercation on West Street and the 32-year-old man has since been arrested on suspicion of murder.
He remains in custody for question
A 33-year-old woman also arrested at the time has been released on bail.
GMP’s professional standards branch, as is routine in such circumstances, have referred the incident to the IOPC who are undertaking an independent investigation into the circumstances.
Detective Chief Inspector, Lewis Hughes, of GMP’s Major Incident Team, said: “We have specially trained officers supporting the family of Adam at this difficult time and our thoughts remain with them.
“Our investigation is in its early stages and we have a team of detectives working tirelessly to establish the exact circumstances that led to Adam’s death.
“I would urge anyone who witnessed the earlier altercation, or has any information that could assist our investigation, to please get in touch as a matter of urgency.”
Anyone with information should call police on 0161 8568797 quoting reference number 113 of 20/04/2018 or the independent charity Crimestoppers, anonymously, on 0800 555 111.