Toxicology shows no presence of 1080 in dead rats that washed up along with other animals on North Beach near Westport this month.
About 600 rats, an octopus, a calf and other animals were found washed up on the West Coast beach on Saturday 9 November.
The Department of Conservation (DOC) sent 12 of the rats for testing over concerns they had been killed by a recent 1080 drop 140km away in Lewis Pass National Reserve.
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Testing was returned today, showing no 1080 in the rats' bodies.
In a statement today, DOC said Maanaki Whenua Landcare Research tested eight dead rats and one weka, none of which had any residue of 1080 toxin.
Two other rats were too decomposed to test.