Weddings in southern prisons are ''rare'', with only a few inmates marrying in the past 20 years.
Department of Corrections Southern regional manager Ian Bourke said prison managers in Otago and Southland could recall three weddings.
Weddings in New Zealand prisons were ''rare''. A national prison poll in 2007 showed 18 prison weddings between 2004 and May 2007.
The three weddings in Otago and Southland prisons were held about 1993, 1998 and 2004, but information on prison weddings was not collected by the department and was ''merely anecdotal'', Mr Bourke said.
A prisoner wishing to marry must obtain permission from the prison manager, who would assess whether the marriage ceremony posed a threat to the security or ''good order'' of the prison.
A maximum of 12 guests was allowed, but the list was at the discretion of the prison manager, Mr Bourke said.
Wedding guests could take pictures of the newlyweds but only in a location agreed by the prison manager, he said.
Weddings were funded by the prisoner, or a source approved by the prison manager. Conjugal visits were not permitted.
''The weddings were often from relationships formed before the prisoner went into prison and was not necessarily from relationships formed during imprisonment.''
The department supported prisoners getting married because positive relationships were important in reducing reoffending, Mr Bourke said.
''The significant role that friends, family and spouses can play in prisoner rehabilitation and reintegration are widely acknowledged.''