Otago Norml spokesman Abe Gray, which runs ''4:20'' protests on the University Union lawn where members consume cannabis, said Campus Watch members had attempted to disband two of the protests last week.
When protesters refused to move or pass on details after they were approached by Campus Watch on Friday, police were called, Mr Gray said.
A Campus Watch member had told Mr Gray the newly aggressive stance was a result of a ''direct order'' from vice-chancellor Prof Harlene Hayne to shut down the protests, he said.
The university did not respond to questions over whether it was attempting to shut down the protests.
Instead, director of student services David Richardson said in a statement a ''complaint was made and investigated'' over the protests.
''Further inquiries are under way, with the police and the proctor involved,'' Mr Richardson said.
Referring to participation in the protest, he said students thought to be in breach of the university's code of conduct or smoke-free policy would be dealt with by the proctor.
Any issues related to non-students would be a police matter.
