The tyres have been collected on the 2ha site by Farmcorp, a business owned by Wanganui couple Te Rino and Jennifer Rapana. Most of the tyres are out of sight, behind a locked gate and vegetation.
After the October investigation, Horizons said Farmcorp did not require resource consent for temporary tyre storage, but asked Mr Rapana to provide evidence the tyres would be recycled. Mr Rapana said they sorted that out, but would not say how.
Last week, Horizons' senior environmental protection officer Greg Bevin said that evidence was not provided because of a family bereavement, which saw the deadline extended.
"It is our understanding that the Rapanas are applying to the Ministry for the Environment's Waste Minimisation Fund to carry out recycling on-site," Mr Bevin said.
"We require evidence of plans to recycle by mid next week. If this evidence is not forthcoming we will need to consider our next steps, which could include an abatement notice."
In a Chronicle story in March, Mr Rapana said the tyres would be converted into a product with many uses. He didn't want to say more in case someone else got hold of his idea.
"We are looking at pulling millions of tyres into this town once we are up and running," he said.
Last week, he said he had moved a lot of tyres out, giving them to farmers to hold down tarpaulins covering silage.
"I have taken probably 2000 to Whangaehu and quite a few to Waitotara."
New Zealand has a problem with an estimated 4.7 million used tyres to dispose of every year, and they have to be shredded before being landfilled. It costs $9 to leave a car tyre at Wanganui's Gilberd St transfer station and more for truck, tractor and four-wheeler tyres.
Neighbours allege Mr Rapana is being paid to take unwanted tyres from regional businesses and people are also leaving tyres at the gate of the property.
Mr Rapana said it was nobody's business whether he was being paid. "I don't ask them how much they're getting paid."
He referred further questions to his business adviser, who did not want to be named but said he was working on a feasibility study for the business.
"Government funding is available to clear the stock of tyres in New Zealand. If the feasibility study is done right and the business model is established, it's something that could work," said the advisor.