Kauri dieback disease has continued to spread throughout the Waitakere Ranges, to the point where they may need to be closed.
A new Auckland Council report says the park is now the most heavily kauri dieback-infected area currently recorded in New Zealand.
The kauri protection zones have failed to slow the rate of expression of kauri dieback symptoms. The infection rate more than doubled in five years, rising to 18.95 percent.
"Despite the significant protection measures in place, kauri infection rates have more than doubled in the last five years, with nearly one-quarter of all kauri in the ranges likely to be infected with this devastating disease," says councillor Penny Hulse.
"As well as considering what this means for the future of the Waitakere Ranges, we must prevent the spread of kauri dieback to other parts of the region that are not yet touched by it. This means stronger protection measures and some very tough decisions."
With no cure for the disease and treatment options still being trialled, the report warns urgent action is needed, and calls for an independent review to investigate banning the public from the regional park.
Other recommendations include upgrading the disinfection stations on popular walking tracks, and assessing the role of wild pigs in the spread of the disease.
While community groups and leaders agree more is needed to save the kauri, they disagree over who's to blame for the spread.
"We must take drastic action now," says The Tree Council secretary Dr Mels Barton.
"The current measures are not working and infection rates have more than doubled in five years as a result of inadequate investment. When the required actions have been undertaken to keep kauri safe then the tracks can be reopened."
Waitakere Ranges local board chair Greg Presland blames the public for failing to comply with protection measures.
"For some tracks, 83 percent of park visitors are walking past cleaning stations without scrubbing their shoes with trigene, going off-track or disregarding closed tracks, making the need for closure more inevitable."
But Forest & Bird says the spread is due to the Ministry for Primary Industry's (MPI's) "shambolic failure" to manage the disease.
"MPI management of the Kauri Dieback Programme has been shambolic, and responsibility for the spread of the disease lies with them. They have shown sustained incompetence at all levels, wasted time and public money and let the disease that is killing kauri spread on their watch," Forest & Bird's Auckland and Northland regional manager, Nick Beveridge, says.
"MPI received $26.5 million from the Government to run the Kauri Dieback Programme. We know that some of this was spent on upgrading tourism infrastructure like boardwalks through infected forests, rather than on funding urgent biosecurity measures."
But MPI strongly refutes claims it hasn't done its job, and says it's disappointed with Forest & Bird's views.
"The Kauri Dieback Programme provides a strong multi-agency government and community response to managing the spread of kauri dieback and the protection of a national taonga," says MPI's principal adviser of conservation, Erik Van Eyndhoven.
"In 2014 the Government announced the allocation of $26.5 million over four years to support the management of Kauri Dieback. Of this funding, MPI receives $4.8 million over four years and this goes towards science and research, national level communications and engagement and staff resources to coordinate the work of the partners. "
Mr Van Eyndhoven says MPI has doubled public awareness of the disease since 2011 and has protected more than 500 hectares of Kauri forest on private land. It's also provided upgrades to at risk sites, including installations of boardwalk and improved drainage.
"MPI along with our partners remain committed to continuing to work with the Auckland Council to effectively manage the further spread of Kauri Dieback now and in to the future."