British police are looking to trace a man over the death of Dylan Crawford (20), from Killygordan in Co Donegal, in Manchester city centre.
Mr Crawford was found unconscious in Spear Street in the early hours of Wednesday and was later taken to Manchester Royal Infirmary.
A post-mortem examination was inconclusive as inquiries continue to establish the cause of death.
Two men arrested on suspicion of theft and supplying prohibited drugs continue to be questioned as police issued a CCTV image of a man they want to speak to in connection with the death.
Detective Inspector Rebecca Boyce, of Greater Manchester Police, said: “Our investigation into Dylan’s death continues and we have now released an image of a man we want to speak to.
“If you recognise him or the clothes he is wearing, please get in touch.
“We are still keen to speak to anyone who was around the Spear Street, Back Piccadilly Street and Oldham Street area between 11.30pm on Tuesday and 12.30am on Wednesday to come forward.
“Even at this time of night the area would be fairly busy, so it is possible that somebody may have seen something.
“No piece of information is too small, and it may be vital to our investigation.”
In a statement issued on Thursday, Mr Crawford’s family said: “Our Dylan was a loving, kind and a very trustworthy individual.
“He saw the good in everyone and that was his downfall.
“He loved to travel and would give the world to anyone.
“He was the heart of our family and words can’t describe how devastated we are.
“Our home will never be the same without him. We love you son, brother, cousin and friend. May you rest in peace darling.”
Anybody with information should contact police on 0161 856 4409, quoting incident number 150 of 12/04/17, or the independent charity Crimestoppers, anonymously, on 0800 555 111.
PA