Tributes are coming in for three veteran ABC newsmen who are believed to have been killed in a helicopter crash in remote South Australia.

Journalist Paul Lockyer, pilot Gary Ticehurst, and cameraman John Bean are feared dead after their chopper apparently crashed near Lake Eyre yesterday evening.

The experienced news crew had been working on news and feature projects in the Lake Eyre region and it is believed their Sydney-based helicopter went down in a remote area about 150 kilometres north-west of Marree about 7:30pm.

This morning police said they had found two bodies at the scene of the crash but said did they did not expect to find any survivors. They said the names of those who had died may not be officially released until later in the day.

Police investigators reached the site overnight but the journey took many hours due to the remote location and bad weather.

It is not known what caused the crash, but there have been reports of bad weather in the area at the time.

This morning ABC managing director Mark Scott said the ABC feared the worst and paid tribute to the men, who he called "three news gatherers at the peak of their craft".

"This has been the longest of nights and we fear it will be the saddest of days," he said.

"I think this is going to be devastating for the ABC. We have been going for nearly 80 years. I don't think we have ever had a day like the day we might be facing, with news of the loss of three distinguished colleagues out reporting a story.

"Paul, Gary and John have each given decades of service to the ABC. They are passionate about their work and finding great stories from all over Australia to bring to the public.

"Our love, thoughts and prayers go out to family and friends of Paul, Gary and John at this terrible time.

"It's been a very long night for their families and for staff here at the ABC as we've waited for news.

This has been the longest of nights and we fear it will be the saddest of days. ABC managing director Mark Scott Embed audio

"These guys were involved on those fabulous documentaries that were made for ABC Television on the blossoming of the desert, Lake Eyre coming to life," he continued.

"They were in Lake Eyre filming more footage for ABC News and Current Affairs, possibly another documentary, to continue to document that extraordinary story of the vast amount of water in the Australian inland.

"These guys loved getting out and about and finding great Australian stories and bringing them to the Australian people.

"That's what they've been doing the last few days and their loss would be a terrible loss to all of us here.

"And so we wait for news, but we have been told not to have much hope."

I fell in love with him on the road and adored working with him. He was so, so talented. I loved watching him at work. So privileged. I can't believe he's gone. John Bean's wife, Landline reporter Pip Courtney

Outback tourism operator Rex Ellis was the first on the scene after the helicopter crash.

He spent the day filming with the crew just before the chopper went down.

"They just took off and went pretty low on the other side of the river and then gradually went out of sight behind dunes," he said.

"We didn't see anything, just saw a glow and we realised that something pretty bad had happened."

This morning John Bean's wife, Landline reporter Pip Courtney, said he was "the most wonderful husband a girl could wish for".

"Devastated, broken, I will be lost without him," she said in a statement.

"I fell in love with him on the road and adored working with him. He was so, so talented, I loved watching him at work. So privileged. I can't believe he's gone. Our families are devastated."

The ABC's Kerry O'Brien said Lockyer was a "consummate professional" and "one of the finest people I've ever known."

"[He was] an absolute gentleman and somebody who cared about the people around him; a fine, wonderful husband and father and just a lovely man," he said.

Three of the best

Long and illustrious careers Watch highlights of veteran journalist Paul Lockyer, cameraman John Bean and media pilot Gary Ticehurst's long and illustrious careers.

Lockyer was one of the ABC's most experienced journalists with an award-winning career spanning more than 40 years locally and internationally.

He had been a correspondent in Washington, Singapore and throughout Asia and won a Logie Award for best TV reporter.

An absolute gentleman and somebody who cared about the people around him; a fine, wonderful husband and father and just a lovely man. Four Corners host Kerry O'Brien on Paul Lockyer

His work in recent years focused on regional and rural issues and his work on the Queensland floods this year won universal acclaim.

Ticehurst is a legend among media pilots - he has served the ABC for more than 25 years and is well liked by all who flew with him.

He had served as the lead pilot for the ABC in Sydney since the mid 1980s and was a larger than life figure who was known by everyone in the news room.

Brisbane-based cameraman Bean has worked for the ABC for 20 years across a diverse range of programs in news and entertainment, including international assignments.

He travelled extensively throughout Australia and the Pacific region for work and last year completed a stint in the Washington Bureau.

ABC News director Kate Torney has told ABC Radio the crash site has been difficult to access.

"Police are at the scene and clearly it took quite a while logistically to get to the scene of the crash. Police have confirmed that there have been two fatalities but we certainly have grave fears for the news that we're likely to receive at some stage later today," she said.

Aviation investigators are leaving Canberra and Brisbane for the crash site this morning.

Neil Campbell from the Australian Transport Safety Bureau says they are working as quickly as they can, but may not arrive until tomorrow.

"They'll be flying to Adelaide first and then we'll be chartering an aircraft to head up to Marree so it will be late this afternoon or even perhaps tomorrow morning," he said.

The tragedy is the worst to hit the ABC since four staff members died in a light plane crash west of Rockhampton in 1983.