The facial recognition software used by South Wales police scans faces in a crowd and compares them against a vast database of custody images.
But out of the 2,470 potential matches, 92 percent (2,297) were found to be "false positives", according to data on the force's website.
South Wales police admitted that no facial recognition system is 100 percent accurate but stressed that no one had been arrested after an incorrect match.
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The police also pointed out that since its introduction the technology had led to more than 450 arrests.
"Successful convictions so far include six years in prison for robbery and four-and-a-half years imprisonment for burglary", a spokesman for the force said. "The technology has also helped identify vulnerable people in times of crisis."
The police said that the accuracy of the system they used has shown to gradually improve over time and blamed the high number of false positives at the football final on "poor quality images" supplied by agencies such as Uefa and Interpol, as well as the fact that it was the software's first major deployment.
"We need to use technology when we've got tens of thousands of people in those crowds to protect everybody, and we are getting some great results from that," the chief constable, Matt Jukes, told the BBC. "But we don't take the use of it lightly and we are being really serious about making sure it is accurate."
