The inquiry into Eastman’s conviction was ordered by the courts in September 2012, after he had served 18 years of a life sentence for the assassination of ACT police chief Colin Stanley Winchester.

Mr Winchester was shot dead at close range in his neighbour’s driveway in 1989, a crime that shocked the nation and sparked a massive operation to track down the killer.

Eastman, a disgruntled public servant who went to see Mr Winchester to try to get an assault charge dropped, was eventually convicted of the murder in 1995.

He has always maintained his innocence, and inquiry head acting Justice Brian Martin on Friday made an extraordinary recommendation that his conviction be quashed. That despite the judge saying he was “fairly certain” of Eastman’s guilt, although he also said he had a nagging doubt.

It can now be revealed that the inquiry, which has undertaken a huge volume of work, has cost the government upwards of $10 million.

The Justice and Community Safety Directorate has spent roughly $3.52 million to date, including the costs for the inquiry itself, the Director of Public Prosecutions, and ACT Correction Services. The costs of Legal Aid, which represented Eastman, have been estimated at roughly $3.14 million. And the Australian Federal Police and ACT Policing have spent roughly $3 million, although their total costs are still being calculated.

Legal assistance for witnesses has also been estimated at $374,000.

That takes the total cost to date for the government to a little over $10 million.

The final report of the inquiry is now in the hands of the ACT Supreme Court. A full bench will use the report to decide on Eastman’s fate.

The three judges who will constitute the full bench were named late on Tuesday as Justices Steven Rares, Michael Wigney and acting Justice Dennis Cowdroy.

It is still unclear when they will make their decision.

If they follow the inquiry’s recommendation, Eastman will be released 19 years after his bail was first revoked mid-trial.

The Eastman inquiry spent more than six months taking evidence from a string of witnesses.

It has revealed “deep flaws” with the forensic analysis that linked gunshot residue in Eastman’s Mazda boot with that found at the crime scene.

Robert Collins Barnes had said the particles in the boot were “indistinguishable” from those at the scene. That has since been largely discredited, and any link between the two has been greatly eroded by the inquiry.

Barnes' evidence was a central part of the Crown’s case against Eastman.

But the DPP and the AFP argued there remained an “overwhelming” circumstantial case against Eastman, even without Barnes’ forensics.