Conservation Minister Eugenie Sage has told media in Wanaka the deaths of the three men in a helicopter crash yesterday was a "huge loss".
Police this morning named those killed in the crash: Scott Theobold, 59, of Twizel; DOC ranger Paul 'Hondy' Hondelink, 63; and pilot Nick Wallis, 38, son of aviation pioneer Sir Tim Wallis.
Ms Sage said the three were "all pioneers in their fields".
"The loss of the huge professional experience of these three men is a huge loss for conservation in Aotearoa as well as for their families."
They were taking part in an operation to reduce tahr numbers.
Police believed there was ammunition on board but Mr Basham said the Transport Accident Investigation Commission (TAIC) would have to answer questions on the state of the ammunition after the accident.
The crash came just three months after Mr Wallis's brother Matthew died when his helicopter crashed into Lake Wanaka. He went missing while on a routine flight to Mt Aspiring National Park in July.
Jonathan Wallis told media his brother loved working in aviation.
"He loved doing what he did and it doesn't make it any easier that he died doing what he loved.
"We're grieving for our own family, for Nick, but also Paul and Scott.
"Our thoughts are with all the families at this terrible, terrible time.
"That is the cruel realty that it's not quite three months since Matt's death
"Aviation is a way of life and unfortunately it can be really unforgiving."
The Department of Conservation said the loss of two colleagues was being keenly felt, as the men who died in Wanaka were well-known members of the DOC family.
Director General Lou Sanson said DOC was devastated by this loss.
"We're stunned and shocked. Our hearts go out to Paul and Scott's loved ones, who are grappling with an unimaginable loss," he said.
"I also want to extend our deepest sympathies to the Wallis family. Nick and the family have been conservation champions and dear friends to the DOC team.
Paul Hondelink had joined DOC in 1987. He started as a programme manager in the threats team in Wanaka, and pioneered judas goat and tahr control work. Most recently he was working as a senior ranger, in the area of biodiversity.
Mr Hondelink was a critical part of NZ Police search and rescue and FENZ fire response.
Mr Theobald started with DOC in 1996 and DOC said he was a world pioneer in the use of dogs to detect predators.
"His first use of predator dogs was at Trounson Kauri Park detecting stoats in 1998," the department said.
From his early work he developed the national predator dog programme in 2000, based in what was the Northland Conservancy. This grew into the Conservation Dogs Programme, which combined Pest Detection Dog and Protected Species programmes.
Mr Sanson said: "We have lost so much. Paul and Scott have some of the most significant conservation experience in the country - if not the world. Thousands of native birds are alive because of them."
DOC said its focus was now on supporting the families and colleagues of the staff lost.
The Wallis family had been linked with conservation their whole lives, he said.
Representatives of the Wallis family were also present at the media stand-up.
Crash investigators said it was too early to discuss the cause of the crash.
A team of four Transport Accident Investigation Commission staff were in Wanaka gathering evidence for the Commission's inquiry into the crash.
Speaking to media this afternoon, head investigator Barry Stephenson said the initial focus had been on protecting and gathering evidence that could disappear or change.
He said the crash site is large and there was a significant amount of debris.
Mr Stephenson said staff hoped to have the wreckage removed by tomorrow. TAIC investigators expected to be in Wanaka until early next week.