A controversial issue of student magazine Critic was described as ''trash and filth'' in internal emails and Otago University proctor Dave Scott expressed his concern about young people reading the magazine.

Copies of the student magazine - the cover of which had a cartoon of a naked menstruating person - were removed from stands around the Dunedin university campus in May and disposed of in a dumpster by members of Campus Watch.

Dubbed Dunedin's ''period drama'' on Twitter, the story was picked up by national news media.

A university spokeswoman said getting rid of the magazines was a regrettable mistake by someone in the proctor's office, not an act of censorship.

The University of Otago has released internal emails about the topic to the Otago Daily Times, which include comments from Mr Scott and two Campus Watch members.

One said they were ''absolutely disgusted that this magazine can 'get away' with such trash and filth''.

''While I am aware that people have freedom of choice, as a Campus Watch member, I feel that we are trying to instil good social values in our students by trying to reduce the drinking culture, helping students to respect one another and to minimise harm to them.

''This magazine and its drinking and drug-promoting culture definitely seems to undermine the values we are trying to protect.''

Mr Scott replied saying that: ''Like you I am disappointed by the Critic this year.''

He said he had raised concerns about both an earlier issue and the menstruation issue.

''I have raised our concerns both with [redacted] and now with this most recent edition.

''I share you concerns about young people viewing the magazine.''

In a letter, vice-chancellor Prof Harlene Hayne said she believed the issue was ''particularly good'' and the actions of Campus Watch were a ''regrettable'' mistake.

''Although these events are regrettable, there is a silver lining here.

''First, this edition of the Critic has received a much wider readership than it otherwise might have, which I view as a really great outcome.

''Personally, I felt the content was excellent.''