Forensic and civil liberty experts have condemned NSW's criminal DNA testing process after a glitch led to a man's wrongful conviction.
A review by NSW Health of its "cold links" system earlier this year found the department's laboratory mistakenly linked a man to a break and enter because of human error.
The system matches DNA evidence collected at a crime scene with people on the state DNA database.
Convicted in early 2008, the man was given a nine-month suspended sentence.
The discovery of the error prompted an exhaustive review of the 17,000 cold links dating back to 2001, when the DNA database was established.
Acting NSW chief health officer Greg Stewart said the review had so far revealed no other errors, and he reassured people the DNA testing system was sound.
Dr Stewart said the mistake was caused by a human sampling error at NSW Health's Division of Analytical Laboratories (DAL) but he stressed the science behind DNA testing was not in question.
"A human error occurred where tests were incorrectly located in a series of tests," he said.
"There are thousands of tests done, and they are done in series of 96 at a time but one of those was out of sequence.
"The wrong crime sample was placed into a well, and that led to DNA from one crime scene being ascribed to a person who was not at that crime scene."
Professor Mark Findlay, director of the Institute of Criminology at Sydney University, said DNA testing was not an exact science and samples were too often relied upon as the only evidence in criminal prosecutions.
"It's very easy for the analysis to be flawed because it goes through several hands and several stages," Prof Findlay told AAP.
"People who look at that science - and they are lay people, judges and juries - are disproportionately impressed by it."
NSW Council for Civil Liberties president Cameron Murphy said police and courts should rely on other evidence to corroborate a crime.
"It's far better for a guilty person to go free than for an innocent person to be in jail because the consequences are so horrific," Mr Murphy told AAP.
Dr Stewart said the man's criminal record had been amended and proceedings had been launched to have his conviction annulled.
The lab technician responsible for the error had since retired, he said.
Dr Stewart said he did not know whether the man would launch legal action to seek compensation over the wrongful conviction.
"There are always openings for people who are convicted to seek redress," he said.
"His options have been discussed with him.
"He'll make his own decision."
Dr Stewart said a similar error in the future was "most unlikely" because of testing improvements, including the introduction of robotics, and the practice of reviewing all case work before results are released to police.
An independent external review would also be conducted by Professor Hilton Kobus, a forensic science expert at Adelaide's Flinders University, Dr Stewart said.
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