A billionaire investor and the Overseas Investment Office have amended the conditions on public access across his land to one of the country's most beautiful beaches.

To get approval to buy his $50 million farm in Northland's Helena Bay, Russian mogul Alexander Abramov promised to provide a legal right of way to the Walking Access Commission.

The public agency was set up after the divisive foreshore and seabed stoush, to protect Kiwis' right to walk our coastlines.

The Overseas Investment Office (OIO) allowed the billionaire steel magnate to buy his 215-hectare farm, north of Whangarei in January 2009 - on condition he provide public walking access over his land in partnership with the WAC. But instead, he has granted the right of way to local iwi Ngatiwai.

One of the routes included a track following the north-western boundary of the property and the coastline from Mohei Bay to Otara Point, near where Abramov's lodge nestles at the water's edge.

The billionaire has developed the property into a country estate complete with a 25-metre swimming pool and palatial guest accommodation, all gated off from the road.

Six years after the approval no easements have been registered with the WAC and documents obtained by the Sunday Star-Times under the Official Information Act show the OIO has instead sanctioned Abramov granting the easements to the Ngatiwai Trust Board.

Wade Doak, a world renowned diver, photographer and environmentalist sometimes compared to Jacques Cousteau, said he had watched developments at Helena Bay with concern. He lives not far away in Tutukaka.

New Zealand was increasingly seen as a "lifeboat for many wealthy foreigners" and he hated the thought of New Zealanders being shut out from the foreshore.

A well-advised Abramov had clearly worked hard to foster good relations with the local iwi, Doak said. He had been amazed Abramov had been granted concessions like the deepening of the bay and the building of a path over the foreshore without opposition from local Maori.

Time would, he added, tell whether the local hapu would administer the track fairly and at arms length from Abramov.

The troubled Mokau Marae, about 5km from the estate, will in practice manage access to most of the route. One large section of the track will be only for the Mokau hapu and "special guests".

The route takes in seven pa sites and several sacred burial grounds making the issue of public access sensitive for Maori.

Abramov has helped the marae in many ways and the project has been a major employer of Ngatiwai members. He says he will continue to employ as many Ngatiwai people as possible.

Ngatiwai also expects Abramov to fix damage to the pa sites on the land caused by previous owners making farm tracks.

Mokau is a divided marae: Sections of the hapu last year applied to the Maori Land Court for an inquiry into finances connected with the marae's building projects and the registrar was instructed to investigate. The matter has yet to be resolved.

The marae's wharenui burnt down in November, 2013, after kohanga reo children set mattresses in the meeting house alight. The rebuild of the wharekai (kitchen and dining room) has stalled. Abramov's contractors have helped the marae with new building plans and helped clean up after the fire.

WAC chief executive Mark Neeson said the commission expected to have a say on any overseas purchase conditions relating to public access to the outdoors for New Zealanders.

"The commission became aware of the proposed amendments after they had been discussed and agreed by other parties. At that point, it was unlikely the commission would obtain any change to the proposed amended conditions," he said in a statement to the Sunday Star-Times.

Murray Horton, spokesman for the Campaign Against Foreign Control of Aotearoa, said he was not surprised the OIO had allowed Abramov to change conditions he had agreed to. The office was known for its retrospective consents, he said.

Auckland-based Abramov representative Chris Seel, who worked in banking in Moscow and got to know Abramov there, said his client was entirely neutral about public access and the access granted under the current easements was no different to what Abramov had originally agreed with the OIO.

"Kiwis have the same right of access to the beach that existed before - nothing at all has changed as a result of the purchase," Seel said.

"It is interesting to note that since ownership changed to foreign hands there have been literally several thousand visitors to the property, far far in excess of the visitor numbers over the prior 100 years under private New Zealand ownership."

Clive Stone, a trustee of the Mokau Marae, denied Ngatiwai would control access.

"The Department of Conservation and the Walkways Commission walked all over our mana by not talking to us about going into our culturally sensitive sites," he said. "We're not worried about what they do outside those pa sites . . .We will not allow anyone to walk all over our pa. It's not about controlling access. It's about controlling access to our sacred sites."

THE BILLIONAIRE

Alexander Abramov founded Russia's largest steel producer Evraz Holding in 1998.

At the company's peak in 2011, Abramov's worth was estimated at $10.2 billion.

Since then, he and business partner Roman Abramovich, the owner of Chelsea Football Club, have seen a downturn in fortunes. According to last year's Forbes, the 55-year-old father of three is now worth just $4.55 billion.