Sensible Sentencing Trust spokesman Garth McVicar is standing by his claim that legalising gay marriage could increase crime, despite a backlash on social media.
Since Mr McVicar's submission to Louise Wall's Marriage (Definition of Marriage) Amendment Bill was made public yesterday, a wave of protest tweets were posted on Twitter, many using the hashtag #gaycrimewave.
Broadcaster Alison Mau, who is engaged to her female partner wrote: "I'm oddly grateful for his help in getting the bill passed."
Labour MP Grant Robertson posted "welcome, all crimes, grammatical or otherwise are a result of my deviance".
And media commentator Russell Brown tweeted: "Crime will rise if gays are allowed to marry, says Garth McVicar ... Garth, I'm so disappointed in you."
Yesterday, Mr McVicar, who is based in Hawke's Bay, said his submission was personal and not on behalf of the trust and he stood by his claims,
"If you look at the court stats, most of the crime that has been committed has been committed by fatherless kids."
He said if the bill is passed, same sex couples may be able to adopt children.
"That's where it's heading - this is just another step in that politically correct journey that we've been on as a country."
It wouldn't matter that some children, if adopted by a gay couple, had two fathers, because they would still need a mother, he said.
Green Party MP Kevin Hague, who sits on the select committee considering the bill, said that of the 20,000 submissions Mr McVicar's was the only one to link gay marriage with crime.
But he said it mirrored a number of other submissions connecting gay rights with an erosion of traditional values, which is associated "in a vague way to various ills in society".
"They are statements of probably genuinely held belief, but entirely absent of actual argument or evidence."
Campaign for Marriage Equality chairman Rawa Karetai said Mr McVicar's submission was "far-fetched".
"I haven't seen any evidence to suggest that and the argument seems to be unsupported."
Mr Karetai said he would be interested to see some peer-reviewed studies on the subject.
Law lecturer Professor Warren Brookbanks from Auckland University said he gave the submission "little credence".
"It's hard to see in any realistic sense how it's going to increase the crime rate. Without more evidence, based on the experience of some other jurisdiction, for example, it's easy to make those statements but difficult to sustain them."
Just Speak, an organisation of young people wanting justice system reform, said Mr McVicar's submission "beggars belief".
"If anything, allowing same-sex couples to wed may increase stability for children growing up in the homes of same-sex couples."
It said Mr McVicar would be better placed addressing issues such as poverty, alcohol and drugs abuse, education, the damaging effects of our high imprisonment rates, and high unemployment.
Mr McVicar made the submission last month.
It said: "I see the marriage amendment bill as being a further erosion of what I consider to be essential basic values and morals that have stood the test of time."
He said the bill represented a further "decay and erosion" of the traditional family that society had been founded on.
"While many of the proponents of this bill also decry the escalation of child abuse, domestic violence, violent crime and corresponding prison population, they fail [or choose to ignore] to see the connection of the social demise caused by the policies they promote and the outcomes."