Millionaire businessman-turned-landscape photographer Richard Green, 74, his graphic artist wife Carolyn, 71, and their friend and filmmaker John Davis, 72, were killed on their way back to Mona Vale from an anti-mining festival in Breeza, south of Tamworth, on Saturday. 

The wreckage of Mr Green's modified EC135 helicopter was discovered on Monday night in rough, mountainous terrain in the Hunter Valley.

The search got under way on Monday after authorities were notified that the privately owned helicopter, which left Breeza on Saturday night bound for Mona Vale had not arrived.

Wallagoot’s Prue Acton, who heads up the South East Region Conservation Alliance (SERCA), expressed her sadness at learning the news of the Greens’ death.

“Richard and Carolyn were dedicated artists and environmentalists and their tragic death is a huge loss,” Ms Acton said on Tuesday.

“They were the most generous of people working tirelessly to document the beauty and destruction of our land.” 

Ms Acton said the Greens first flew to the Bega Valley in 2011 to photograph Far South Coast forests to help build awareness of the plight of the southern koalas.

“Logging in state forests from Mumbulla to Gulaga Mountains is the major cause of the current low animal numbers of 60-80,” she said.

“The panorama Richard created has become the iconic image of the Far South Coast.

“I am personally deeply saddened by Richard and Carolyn's tragic death as we had become great friends as well as fellow environmentalists. 

“I saw them in Melbourne at the opening of my exhibition – they purchased one of my works and we three had an intimate conversation.

“I can see them still.”

Tanja local Vincent Weafer said Mr Green’s panorama is “stunning” and rightfully deserves a place in the lexicon of iconic environmental images.

“I have always found that photo changes people’s perception of our region and their perspective of our environment,” Mr Weafer said.

“It’s like that wonderful photo of the Franklin River [by Peter Dombrovskis] that was used by the Tasmanian Wilderness Society to halt the proposed dam and even helped bring down the government.”

A friend of killed veteran filmmaker John Davis, Dr Brian Spies, said the purpose of the helicopter flight was to film coal mines in the area for a documentary they were working on.

Mr Spies said Mr Davis and fellow environmentalists Mr and Mrs Green were planning to use the footage to expose the environmental damage wrought by the coal mines.

Ms Acton said the Greens’ work in highlighting the plight of the Australian environment will continue after their death.

“In June this year, they came to lunch and then we flew off in their helicopter, along with environment photographer David Gallan,”  she said.

“I  was selecting the locations, Richard rotating the helicopter and Carolyn shooting with a really heavy camera.

“Later Richard ‘stitched’ together the series of photos into one panorama - that is the art of his work.

“These images are to be used for a new proposal, The Great Southern Koala Forests, connecting national parks, state forests and providing corridors for hundreds of vulnerable and endangered wildlife species from the Great Eastern Ranges to the coast from south of Sydney to the Victorian border.”

The Australian Transport Safety Bureau said three investigators were travelling to the rugged crash site this week to search for clues as to how the helicopter crashed.

The Australian Maritime Safety Authority said there had been no mayday call or emergency distress beacon signal from the privately-owned helicopter.

Mr Green modified the helicopter into what he called his "flying campervan" for him and his wife to travel around Australia.

- with Rachel Olding, Sydney Morning Herald