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An email from University of Otago proctor Dave Scott, passed to the Otago Daily Times, said initiation season was ''upon us'', and urged both flatmates and guests to be careful.
The email was addressed to students, and Mr Scott confirmed it had gone out to halls of residence to be distributed.
''Often there is a power imbalance, with guests being forced or coerced into dangerous, antisocial and often unlawful behaviour,'' Mr Scott said in the email.
''I genuinely fear that unless significant changes are made there will be a student death. History would tell us that a death is often the catalyst for a culture change in these matters - I am seeking a change before a tragedy occurs.''
Flat initiations were held in September and October, when students signing up for flats for the next year were initiated by the existing flatmates.
Last year, initiations led to disciplinary action against 17 University of Otago students, including nine exclusions.
At the start of the year, students were excluded for a 2017 initiation dubbed ''sadistic'' by Mr Scott.
Hundreds of students cheered as people with their heads shaved stripped down to their underwear and skulled drinks until they vomited.
Otago University Students' Association president Caitlin Barlow-Groome said second-year flat initiations were ''fairly common'' but the majority were held in safe conditions.
OUSA student support manager Sage Burke said problematic initiations usually involved challenges and excessive alcohol.
Under the university's Code of Conduct alcohol and drug consumption as part of an initiation ceremony is forbidden.
The email told hosts to consider the safety and legality of the events they held, and whether pressure was being placed on their guests.
Mr Scott also reminded guests that initiations had nothing to do with their tenancy agreements and they did not have to participate.
He would be visiting flats involved in ''poorly-run events'' in the past to deliver the message.