Reg McCormack approached the Otago Daily Times yesterday to find out what happened on the night his son died.
He provided a photograph of his son in the shirt he was wearing that night.
He said he was very close to his son and it was hard not knowing what had happened to him.
Mr McCormack said his son was careful and responsible.
He said he could not understand why Regan (20) would have been walking to Waverley, or have been in the area of the Steamer Basin, where his body was found.
His son had never before walked home to Waverley after a night out, and he had not slept at the family home for more than three years.
In fact, his bedroom had been turned into an office.
Mr McCormack said the amount of alcohol his son had consumed was not enough to make him "staggering drunk".
Regan had attended a friend's birthday at the Starters Bar on the corner of Frederick and Clyde Sts on the evening of Thursday, July 9.
He left the bar between 12.30am and 1am.
He was last seen walking towards St Andrew St, via Leith St.
He was wearing a white shirt with thin stripes and close-fitting jeans.
Police understood he was walking home when he became disoriented and fell into the harbour.
His death was not being treated as suspicious.
His body was discovered by workers repairing a boat at the Fryatt St wharf at 10.50am the next day.
Mr McCormack asked anyone who had seen his son walking near St Andrew St, or the Steamer Basin, to contact the Dunedin Central Police Station.
