On Monday about 10.10pm, a 19-year-old University of Otago student was on the roof of a Castle St property taking pictures with some friends when he lost his balance, slid down the roof and fell, Sergeant Matt Lee said.
A friend, who declined to be named, told the Otago Daily Times that the student had just returned from Christchurch after playing in a rugby tournament for the Southland under-19 team.
The Southland team had games against Canterbury and Tasman over the previous few days.
After returning to Dunedin, the team had gone to a Castle St flat, known as "Big Red", and started drinking.
Most of the people who were at the gathering stayed inside while a few went to the roof to take photos.
Hato Hone St John and police attended the scene and the teenager was transported to Dunedin Hospital in a critical condition.
Police inquiries into the incident are ongoing.
A University of Otago spokeswoman said their thoughts were with the student and his family.
