The Government has apologised for failing to recognise the significance of Mount Ruapehu while engaging with iwi over the future of its skifields.

Documents released to NZME under the Official Information Act show then-Regional Development Minister Kiri Allan wrote to iwi representation group Tūwharetoa, apologising for a 'flawed' engagement process in relation to the sale of the two ski fields on the mountain.

Ruapehu Alpine Lifts, which runs the Whakapapa and Turoa ski areas, went into voluntary administration late last year, owing about $45 million.

It was agreed to be liquidated by creditors in June after options to take over management of the company failed to gain enough support at a watershed vote.

The letter to Tūwharetoa was sent after iwi met with the Department of Conservation's Regional Director on 20 June, discussing the further steps in the bidding war.

The iwi representation group had outlined "overarching frustration" with the sale and purchasing process to the conservation authority.

Treaty Negotiations Minister Andrew Little and Conservation Minister Willow-Jean Prime co-signed the letter with Allan.

The letter, which has not been released publicly, notes concerns about consultation with mana whenua.

"We apologise for the impact this has had on you and your communities," the Ministers wrote to iwi.

"We acknowledge that the process has not met the standard of rigour that you should expect from the Crown as it has not allowed appropriate time and quality information- two fundamental elements of good engagement."

Uenuku Chair Aiden Gilbert, located in the nearby area, believes the politicians 'needed' to share their apology.

"The consultation was minimal to say the least- it needed some meaningful consultation from the very beginning," Gilbert told NZME.

Allan, Little, and Prime promised things would be done differently: "We know that Te Arawhiti will certainly be addressing some of the issues that arose through this process- so we are all able to learn from it and work harder to ensure it doesn't happen again," the letter read.

The Ministers summed up concerns from iwi, following their meeting with DOC. They wrote iwi believe the Crown has paid a lack of attention to the "integral relationship" between Ngāti Tūwharetoa and their mountain.

Iwi expressed "specific frustration and disappointment" at a lack of engagement by the Crown regarding Ruapehu's cultural significance.

Gilbert said Mount Ruapehu had extraordinary significance to Māori.

"It's important because it touches the sky. It's important to us because it's significant as a place of tapu," Gilbert said.

"I remember my koro saying 'don't go up there and play-  that's where our fresh water comes from," he reminisced.

The iwi leader said the issues surrounding consultation weren't new, claiming a variety of laws had 'muddied the waters' on what real engagement looks like.

The revelations come after a $5 million government loan from the Government, allowing the liquidators of Ruapehu Alpine Lifts a lifeline to get skifield operations off of thin ice, whilst bidding continues.

At the time, the Regional Development Minister announced Pure Tūroa and Whakapapa Holdings were the preferred bidders with the prospect of opening the skifields under joint operation.

The letter of apology released under the Official Information Act also came alongside a strongly-worded letter from disgraced MP Kiri Allan, towards MBIE Chief Executive Carolyn Tremain.

It states Allan's "concerns" with how Kānoa, the Regional Economic Development and Investment Unit under MBIE, had been dealing with the process.

The Regional Development Minister at the time said MBIE should frequently engage with all other relevant Government agencies."Specific risks in relation to Treaty relationships may be been identified earlier in the process, had Te Arawhiti been appropriately engaged some time ago," the politician told Tremain.

On the day of the $5 million loan to help Ruapehu operate this season, Kiri Allan spoke to Newstalk ZB on the importance of tangata whenua agreeing to any potential transfer agreement.

"I disagreed with MBIE's approach and therefore instructed Te Arawhiti and the Department of Conservation to get into the room to make sure that they could manage that concession," the then-Minister said.

Uenuku's Chairperson was not convinced the Ministry of Business, Innovation and Employment had "really ticked the box."

In the letter, Allan said there was an expectation Crown Law would be involved in the ongoing bidding war, to provide legal advice. Kānoa had been receiving independent legal advice on the issue from Chapman Tripp.

A Department of Conservation spokesperson said it's 'not appropriate' for the Department to comment on Ministerial matters. MBIE has been approached for comment.