Two experts have given conflicting evidence on whether they believe a fingerprint at a murder scene belonged to former detective Shirley McKie.
The fingerprint has split expert opinion
Dutch police expert Arie Zeelenberg told a Holyrood inquiry the print could not have been Ms McKie's as it contained more than 20 differences.
However, fingerprint expert Peter Swann said Mr Zeelenberg's theory was flawed as he used the wrong print measures.
Ms McKie was awarded £750,000 in compensation over the case.
The former policewoman, from Troon, in Ayrshire, was cleared of lying on oath in 1999 after insisting that a fingerprint found at a murder scene in Kilmarnock was not hers.
Ministers called the misidentification an "honest mistake".
Six of the experts giving evidence to the inquiry believe the print found at the Kilmarnock home of Marion Ross was not left by Ms McKie.
But others, including a former Home Office expert she hired, insist it was.
Giving evidence on Wednesday, Mr Zeelenberg showed a presentation identifying a number of discrepancies between the disputed Y7 print, which was found at the home of Kilmarnock murder victim Marion Ross in 1997, and Ms McKie's.
He claimed that Scottish Criminal Record Office (SCRO) experts had "invented" comparison points to support their position.
He said: "There are 20-plus differences. There's numerous differences in ridge detail and invented points marked by SCRO and this is what you may expect with fingerprints coming from a different source.
"The nature of some of the differences like 19 and 20 stand out."
Mr Zeelenberg addressed the issue of "cropped" images of the disputed print presented previously by the SCRO experts.
These led to claims that the Scottish experts had been trying to hide clear differences in the cropped areas between the disputed print and Ms McKie's.
Mr Zeelenberg said: "Point 19 and 20 are conveniently brought out of sight. The big ones."
He said this indicated that the Scottish experts were being dishonest.
"I must conclude in general that the presentation of productions was not professional, not transparent, not honest, misleading and wrong and this shows awareness of a large number of discrepancies," he added.
Mr Zeelenberg also said that five separate clusters of similarities between the two prints, which were identified by the SCRO experts, were all out of sequence.
"Fingerprint detail has to be in sequence. That's the essence of it."
But if this evidence was to be accepted, then Ms McKie must have planted her print five times over, said Mr Zeelenberg.
"If Shirley McKie was able to do that you should award her the Nobel Prize. It is impossible. The tip is then from somebody else."
However, Mr Swann said experts who did not believe the print was Ms McKie's were wrong because they had not used rolled prints, in which the finger is rolled as the print is being taken.
Referring to the original print, which had been found on a door frame in Ms Ross' home, he said: "I saw the door standard, on the door standard is the left thumb print of Shirley McKie.
"It was quite clear in my opinion that it was a genuine mark, it hadn't been forged or planted."
He said there had been movement in the mark found in Ms Ross' home, distorting the fingerprint.
Mr Swann said he and another expert working on the case had found 32 matching characteristics.