So called "slam-dunk" evidence seized on by the David Bain camp to push his case for compensation appears to have left the Government unmoved.
Senior government sources appear to be backing the police view that there is "nothing new" in the case made by TV3's 3rd Degree show.
The show claimed parallel markings on Robin Bain's thumb were consistent with him firing a gun that morning.
Tests loading the magazine of a rifle shortly after it had been fired were said to mirror the marks.
David Bain was imprisoned in 1994 for 13 years after being convicted of killing five members of his family.
His supporters have always claimed it was father Robin Bain who committed the crime.
In 2007 David Bain's conviction was quashed by the Privy Council in 2007, and when he was retried in 2009 he was found not guilty.
Bain is seeking compensation after being acquitted, but the Government rejected an initial report by Canadian judge Ian Binnie which concluded that it was "probable" David Bain was innocent.
A second inquiry into the compensation claim is now under way.
A senior government source told Fairfax Media the 3rd Degree claims were unlikely to change the course of that inquiry.
"I find it hard to believe the prosecution didn't see that; they had lots of time [19 years] to look at it."
The Government's rejection of the Binnie report caused controversy but the source said the test for compensation was "quite different" to being acquitted on charges, which only required reasonable doubt.
That was why the Bain camp was determined to show it was Robin, not David, who pulled the trigger.
"You've actually got to prove someone else did it... and if you read Binnie's report there is actually nothing in it that points to David not doing it.
"The report says it's either David or Robin, no one else. All the evidence, it's all circumstantial, but there's still a lot more of it pointing at David than pointing at Robin. But let's see."
- Sunday Star Times