Debate is raging over how many people have managed to access gun owners' private details on the buyback platform.
The German software provider has apologised and blamed it on human error but says only one dealer got hold of the information.
However, gun rights advocate Mike Loder says dozens of people had access to it, screen shots were taken and it was being downloaded for hours after it was reported.
Prime Minister Jacinda Ardern told Mike Hosking she's heard that too.
She says she's queried it again and has been reassured just one person accessed the details.
"The software provider SAP has admitted it's their fault. They have called it a human error, but we have been let down by this breach."
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