The marriage at an Auckland prison between the rapist and murderer Liam Reid and his former lawyer Davina Murray is revolting, the Corrections Minister says.
Reid is serving a 23-year sentence for killing Christchurch woman Emma Agnew in 2007 and for raping and attempting to murder a university student in Dunedin nine days later.
Davina Murray was convicted and struck off as a lawyer after she smuggled an iPhone, cigarettes and a lighter into Mt Eden Prison for Reid in 2011.
Corrections Minister Louise Upston said her thoughts were with Ms Agnew's family today.
"I just find it revolting, I find it absolutely distasteful.
"Unfortunately it's not illegal to get married in this country but actually I think her family, it will be an absolutely tragic day for them because they know they will not see their daughter get married, and I think it is absolutely appalling."
Ms Upston said there needed to be a greater level of rigour involved in deciding who was allowed into prisons.
"In this instance, she [Davina Murray] is convicted of [taking] contraband into a prison, and there was a ban in place.
"I'm actually quite keen to look at whether lifetime bans for people who take contraband into prison is an option," Ms Upston said.
The minister said she was not notified the marriage was taking place.
Corrections deputy prison director Tom Sherlock said the wedding was scheduled to take place today.
"A prisoner is allowed to marry their partner with the permission of the prison director, who considers whether the ceremony poses a threat to the safety, security or good order of the prison," Mr Sherlock said.
"Although a rare occurrence, weddings or civil union ceremonies are not restricted in prisons and each application is considered on a case by case basis - the appropriate security measures will be in place."
Labour Party corrections spokesperson Kelvin Davis said prisoners had the right to get married.
"Everyone's feeling a bit squeamish about it. But there must be some sort of rigorous process that they go through in order for the prison to agree for them them to be married and I guess if that process has been covered off well then it's been covered off."
Mr Davis said he expected the wedding would be a barren affair and not what most people would consider a celebration.