Police dispute that thumbprints uncovered by Joe Karam supports his theory that Robin Bain is guilty of the Bain family murders on June 20, 1994.
Mr Karam says the new set of prints of Robin Bain's thumb supports the evidence of a photos revealed on June 26, which David Bain supporters said show gunpowder marks caused when reloading the .22 rifle used as the murder weapon.
Police produced a fingerprint they said supported their rival theory the marks were caused by a earlier, minor DIY home rennovation injury.
Assistant Commissioner Malcolm Burgess is also dismissive of the new prints.
"The fingerprints of Robin Bain taken on June 21, 1994, and released by Mr Karam [yesterday] were taken by a detective," he said in a statement last night.
"These were examined by a police fingerprint expert at the time who determined they were not of adequate quality."
That fingerprint expert then took two further sets of prints on June 22, 1994. These are the quality prints which have always been relied on in this case by fingerprint experts, the assistant commissioner said.
A copy of the right thumb print from one of these sets taken by the fingerprint expert on June 22 was issued by police following last month's 3rd Degree TV programme.
Police are applying for access to all of the original prints, Mr Burgess said. These are held by the court, not by police.
"These will be examined thoroughly to see if they assist in determining the nature of the marks on Robin Bain's thumb," he says.
"Police have made it clear there could be several possibilities to explain these marks. Right now, any explanation for them remains a theory.
"While it is hoped the examination will provide greater clarity, it also remains a real possibility that even after the originals have been examined there will still be no definite conclusion regarding the marks."
It would have been helpful if Mr Bain's supporters raised these issues direct with police for clarification before launching them into the media with claims of wrongdoing or incompetence, Mr Burgess said.