He fell about 10m from the second floor of the Glebe Apartments and Luxury Penthouse complex on to the concrete car park below, sustaining a major head injury, police said.
''He was making his way from his second floor apartment towards the roof,'' Senior Constable Chris Blackford said yesterday.
Police and St John were called to the hotel shortly before 3am and the teenager was taken by helicopter to Dunedin.
Members of his family have travelled from Australia to be with him.
Police, who have completed their inquiries into the incident, confirmed he was staying with friends at the hotel and the group had been drinking alcohol before the incident.
Meanwhile, the hotel manager has implored youngsters to stop climbing on buildings.
General manager Anne Henley said staff were in a state of shock after the second major alcohol-related fall at the Stanley St complex in six years.
''When will these kids learn not to climb?'' Ms Henley said.
''The night manager found him, who is naturally in a state of shock. We all are. It's awful. There was another one who fell here a few years ago.''
Ms Henley, who has managed the complex for almost 13 years, says the Australian teenager was a guest at the Glebe.
''He's a guest but I'm not 100% sure exactly where he fell from,'' Ms Henley said.
''He was making his way from his second floor apartment towards the roof,'' Senior Constable Chris Blackford said yesterday.
Invercargill electrician Shaun Hogan (24) fell to his death at the Glebe after gaining access to the courtyard and climbing to the roof in 2008. His friends described him as ''quite intoxicated'' at the time.
In 2009, English backpacker James Smith (25) fell about 10m to his death from the roof of Base Backpackers on Shotover St, in the resort.
Police believe he was intoxicated.
