Robin Bain supporters have filed a complaint with TV3 about a television show claiming re-examined evidence could clear his son David of the family's murders.
Melanie White, of the Justice For Robin Bain Facebook group, confirmed the group had lodged a complaint against 3rd Degree, which screened on Wednesday at 8.30pm.
The show claimed "a newly re-examined photo of Robin Bain's hand could vindicate his son David from killing his whole family, and help him get compensation for the 13 years he spent in prison".
3rd Degree argued that parallel markings on Robin Bain's thumb were consistent with him firing a gun on the morning of the murders. The marks - not noticed in the 19 years since the murder - matched those made by gunpowder residue when loading the magazine of a rifle shortly after it had been fired.
A Dunedin member of the group instigated the action, which they allege breached three standards of the Free-to-Air Television Code of Broadcasting Practice.
The group alleges the show breached standards for controversial issues, accuracy and fairness, Ms White, of Dunedin, said.
"We want to make people aware of the terrible reporting that TV3 has done. It was so biased."
If the group was not happy with the broadcaster's response, it could take the complaint to the Broadcasting Standards Authority (BSA).
TV3 director of news and current affairs Mark Jennings said he was not aware of any formal complaints about the programme.
"The BSA accepts that there is a 'period of interest' after a controversial story where different viewpoints can be aired."
"I also expect we will do more on this week's 3rd Degree. We absolutely stand by the programme."
Police, when asked, said the option of a formal complaint had not been considered yet.