Responding to the rising spread of coronavirus from mink to people, including a new mutated strain, Frederiksen's Social Democratic government in November 2021 ordered all of the country's 17 million minks killed.
The government later admitted it did not have the legal authority to kill healthy mink herds, only those infected with coronavirus, leading to the exit of the minister of agriculture.
Parliament launched a probe in December into whether other ministers including Frederiksen knew of but ignored the faulty legal basis for the order.
"What motive should the government have had for not disclosing the lack of legal basis? Let me make it very clear: I did not know," Frederiksen told a press briefing, offering her most detailed defence so far.
Prior to the slaughter, which left the industry in ruins, Denmark was the world's largest producer of high-quality mink skins, coveted in the fashion industry for their silky-soft character.
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Opposition lawmakers have accused the prime minister of deliberately working against the probe.
Investigators wanted to review text messages sent by Frederiksen and officials in her office but said they had been deleted because the officials set their phones to erase texts after 30 days. The Justice Ministry is working with police to recover the messages.
"Will those text messages show anything new about my knowledge of the lack of legal basis? No, they will not," Frederiksen said.
That probe, which will put Frederiksen on the stand on Dec 9, is set to present its conclusion in April.
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