There is a raft of regulatory hurdles to overcome, the property is likely to be publicly advertised for sale, and, ultimately, final approval is required from Conservation Minister Eugenie Sage.
Three weeks ago Ms Sage canned an expansion project at Oceana Gold's Waihi gold mine, which now threatens to close it prematurely, rattling the mining industry and its future outlook for gaining consents.
Farm land over 5ha is considered ''sensitive land'' under the Overseas Investment Act 2005 and requires sign-off from Ms Sage, as Land Information Minister, and Associate Finance Minister David Clark.
The pair disagreed over Oceana's Waihi application, so it was automatically declined.
Australian company Plaman Resources owns a small diatomite mine within 42ha on Moonlight Rd, near Middlemarch, but has an agreement in place to buy 432ha of Foulden Hill farm, which surrounds the mine and from which the mine was subdivided many years ago.
Foulden Maar, once an ancient volcanic crater lake, is laden with fossils, prompting a call to have it protected and designated a Unesco World Heritage site.
Should the farm surrounding the mine come up for public sale, a crowd-funding project could, in theory, save it, as happened in 2016, when $2.25million was crowd-funded to purchase Awaroa Bay, which later became part of the Abel Tasman National Park.
An online petition to save Foulden Hill had about 8600 signatures yesterday.
Plaman's lack of disclosure during the past year not only raised the ire of some Middlemarch residents, but now that of the scientific community and environmentalists.
Plaman squandered another opportunity this week in pulling out of the annual Minerals Forum conference in Dunedin, a senior delegate saying the company should have engaged a specialist New Zealand consultant to manage its OIO application and public disclosures.
Some Middlemarch residents, who did not want to identified, believed Plaman may have bypassed due process in making an offer for Foulden Hill farm, and that it had to be advertised for sale publicly first.
Land Information New Zealand group manager Vanessa Horne, of the Overseas Investment Office (OIO), said when contacted she was unable to comment specifically on Plaman's application.
But speaking in general of the process, she said an overseas investor could enter an agreement with a farm seller to buy the land, subject to OIO consent.
''[However] the vendor must then genuinely advertise the property and the vendor must be able to accept an offer from a New Zealander,'' Ms Horne said.
She noted advertising had to comply with overseas investment regulations, such as there could not be terms in agreements which allowed an overseas person to match any offer made by any New Zealanders.
''If farm land hasn't been advertised, or a farm land advertising exemption has not been applied for, an application would not be accepted for processing,'' she said.
Similarly, an investment would not be approved without the farm land advertising requirements having been met, Ms Horne said.
She was unable to comment on the Plaman application because it was ''currently being assessed'', nor release any information until a decision was made, which would be made public.
The Plaman application was lodged in February 2018, with wait times on average of several months, but Plaman's application was ''more complex'' than average applications, the OIO has said, without providing any further details.
