Joe Karam, who fought to overturn David Bain's murder convictions, says marks on Robin Bain's thumb could not have been injuries as they had disappeared by the time his body arrived at the mortuary.
Mr Bain spent 13 years in prison before being acquitted of killing his five family members at their Dunedin home in 1994.
His supporters say photos show that marks on his father Robin Bain's thumb were caused by gun powder residue.
The police said on Monday they could have been caused by pre-existing damage or injury to the skin.
But Joe Karam says the pathologist says the marks were not there two hours after the photos were taken.
He says Mr Bain's compensation bid is stalled while his application for a judicial review is heard in the High Court.
In June the TV3 programme, 3rd Degree, said photos showed that marks on Robin Bain's thumb were caused by gun powder residue from a firearm's magazine used in the homicides.
This would mean that Robin Bain killed his family, and then himself.
But Assistant Commissioner Malcolm Burgess says the most likely explanation would seem to be pre-existing damage or injury to the skin on Robin Bain's thumb.
He says the latest tests were carried out using accredited experts in controlled conditions, with access to the original exhibits and in the presence of Mr Bain's advocates.
Mr Burgess says they show the marks are anything but the game changing-evidence they were claimed to be.