The family of a man originally believed to have died at home from natural causes in 1993 say they are "deeply shocked" after a recent arrest.
South Wales Police have opened a new investigation into the death of Stephan Hinc, 40, from Riverside, Cardiff, after fresh information came to light.
A 48-year-old man from Penarth, Vale of Glamorgan, arrested on Wednesday has now been released on bail.
Mr Hinc's family said they were still "coming to terms" with developments.
Mr Hinc died in Coldstream Terrace, on the opposite side of the river to the Millennium Stadium.
The arrested man was questioned at Cardiff Bay police station.
After he was given bail until 2 August, police said they were making further inquiries and also waiting for advice from the Crown Prosecution Service.
In a statement released through police, Mr Hinc's family said: "We are fully supportive of the police investigation, but are of course still deeply shocked by these recent events.
"We are still coming to terms with the news, and would kindly ask that our privacy is respected at this difficult time."
They are being supported by a family liaison officer.
Anyone with information in relation to the investigation can contact the incident room on 029 20571 583, or 101, or Crimestoppers on 0800 555111.