''It is clear that alcohol and altitude don't mix,'' he said.
The group had shimmied between two rain-soaked buildings before climbing a fire escape to access the roof, a practice that is believed to be promoted via social networking sites.
The latest incident comes almost a year since Octagon Chambers barrister David More told the Otago Daily Times that ''something more serious may happen'' following a similar incident when three drunk students were nabbed on the roof.
''This has been a problem for a couple of years, but it is only last year and this year it has been more than a joke,'' he said yesterday.
Booze and rubbish had been left on the roof and, once, a window had been smashed and beer taken from a refrigerator.
Although those involved in last year's incident received diversion, it was now ''beyond a joke and should be frowned upon''.
Mr More said he planned to talk to the building manager in an effort to improve security.