"The group was moved on by police and there was no fighting and no arrests.''
Botanic Garden team leader Alan Matchett said he was present at the gardens when police attended, but he could not comment on what happened.
It is understood a keg party was held at the gardens with several empty kegs discarded afterwards.
University of Otago proctor Dave Scott said any students who were out of line at the event would be punished.
"Any student who is found to have acted inappropriately will be subject to the University's Student Code of Conduct,'' he said.
A Dunedin City Council spokesman said it was "disappointed'' by the behaviour of those involved and it would be assessing the area tomorrow to check for damage.