Abseilers were among workers who spent nearly three days retrieving more than a thousand tyres dumped off a road near Clevedon.
It is one of a spate of recent illegal dumping incidents suspected to be by commercial operators.
Strewn through native bush and down a ravine fringing Twilight Rd were 1285 tyres.
The road was closed during the clean-up which Auckland Council estimates will cost ratepayers $25,000.
In addition to the tyres, 3.8 tonnes of general inorganic waste was collected. Specialist manpower and equipment used included four abseilers and a 3000kg Palfinger crane truck.
The tyre dump was spotted by the Herald last month during scouting for its Trash town series.
A council spokesman said the tyres were taken by Waste Management NZ to its tyre-shredding plant at Wiri.
Mayor Phil Goff visited the site of the dumping and said the amount of tyres meant it could only come from a commercial outfit. "Illegal dumping is disgraceful. It harms our environment and costs the ratepayer thousands each year to clean up," Goff said.
"Council has invested an additional $200k to help tackle this issue, with more surveillance cameras, stronger enforcement and speedier clean-ups. We've also set up 0800 NO DUMP – a dedicated hotline to report illegal dumping.
"We need Aucklanders to report it when they see it and send any evidence they have to Council. I want to see those responsible for this sort of behaviour held accountable. With enough evidence, prosecution is a real option."
The council is yet to prosecute for incidents in which leaking oil drums were dumped on roadsides near Ardmore and Piha in January and a huge pile of household trash was tipped on to the driveway of historic Ferndale House in Mt Albert.
A council spokesman said these investigations were progressing well but divulging more information might jeopardise potential prosecutions.
The council brought only two prosecutions last year under the Litter Act 1979, which provides for fines of up to $30,000 for a company and $5000 for an individual.
"That's not enough and I have told staff I want that lifted," Goff told the Herald last month.
The Council also issued $20,000 in instant fines but in an average year it is able to collect less than half.
More than 1300 tonnes of illegally dumped rubbish is collected each year at a cost exceeding $1 million.