Philip Tebbutt, who owns the Virginia Lodge Rest Home next door to Otamatea Reserve, denied he would have ever used rat bait.
"That is just absolute rubbish," he said.
"We've got dogs and cats here as well. If anyone's going to get poisoned it would be mine.
"To be fair I'm here all the time ... I haven't seen a rat running around my place. We do have mice traps out and we do get the odd mouse but the cats keep them down fairly well."
Tebbutt said he'd never had contractors or anyone from outside his rest home that could have used rat bait.
"I do it all myself. I do all the trimming, the mowing, the hedges, general maintenance. It's not possible it could have come from this place - not at all.
"I spoke with my nurse manager and she and her partner had run it here for the last 25 years and they'd never put rat baits out. She was horrified."
Tebbutt said it was more likely that if rat bait had made its way to Otamatea Reserve it would have come from one of the households surrounding the park.