Association president Hugh Baird said representatives approached the Elohim Bible Academy - a subgroup of the World Mission Society Church of God - about concerns which had been raised by students.
''We have had quite a few complaints come through from a whole lot of people around campus about the nature they have been operating in,'' he said.
''It goes against our constitution.''
The OUSA had had ''quite a few conversations'' with the group following the first issues arising in April, but those directives had not been followed.
''There's been plenty of conversations back and forward, where we have allayed our concerns and it was a final step that we had to disaffiliate,'' Mr Baird said.
''They said they would go away and fix [the problems], but they didn't.''
The group was formally disaffiliated last Tuesday.
The decision would mean the group could not access OUSA funding or attach the association's name to its activities.
Critic reported the group commonly attempted to recruit members by door-knocking in the North Dunedin area.
The church believed in the teachings of South Korean man Ahn Sahng-Hong, who they claim is Jesus Christ in second coming.
Criticism has been directed at them for their ''forceful'' nature when door-knocking, presenting false information and pressuring people into uncomfortable situations, Critic reported.
A representative of the group refused to comment when contacted by the Otago Daily Times and hung up their phone.
University of Otago proctor Dave Scott had investigated trespassing members of the group from campus grounds, but ruled it out.
''The New Zealand Bill of Rights Act 1990 allows for freedom of religion, freedom of expression and freedom of manifestation of religion and belief,'' he said in an emailed reply to ODT questions.
''As a result, no-one has been trespassed from the [University of Otago].''
The university played no part in the OUSA's decision to disaffiliate the group. And when asked if the university had any concerns about the group, Mr Scott replied: ''No.''
''The message to students who are unwantedly approached by anyone, whether it be surrounding religious affiliation or attempting to sell timeshare accommodation in Queenstown, is to politely say no and not engage.''
Mr Baird said the group could gain OUSA affiliation again if it showed change.
''If they can come back to us and prove they have taken our comments on board and are willing to operate in the way we have expressed, then we are happy to look at taking them back,'' he said.
