The trio rescued from an isolated Southern Ocean beach this morning after their helicopter crashed last night near the Auckland Islands have walked into Southland Hospital in Invercargill.

The men arrived in two helicopters just before 4pm.

The three men, two with helmets on and one without, all wearing orange jumpsuits climbed from the Otago Regional Rescue helicopters and walked into the hospital unaided.

Media at the hospital were told by security to stay back from the scene.

John Lambeth, a St John paramedic, was onboard the aircraft with pilot Andrew Hefford and winchman Lester Stevens when it went down near Yule Island, at the northern end of the subantarctic island group.

Senior Search and Rescue Officer Dave Wilson told Heather du Plessis-Allan that the three are currently receiving medical treatment. 

"From what we understand, one of them had suspected broken ribs and a wrist, another one perhaps a broken nose, and the third crew member from what we understand was uninjured."

Wreckage was discovered this morning by a fishing boat and the trio were spotted sooner after, alive, walking on a beach, around three kilometres from where the wreckage was found. 

Wilson says that it is "very fortunate" that they were walking around afterwards. 

He says that they have little information, only from the tracking they saw last night. 

"We understand that they were flying into that area, they were going to be doing another job, a medical evacuation on a vessel, and before they arrived on the island, something has happened that caused the aircraft to crash into the water."

There was no distress signal sent out, but they do not know why.

"It's too difficult to determine at this stage," Wilson says, adding that the accident investigators will advise once they have spoken with the crew. 

In a statement, St John said Lambeth was a paramedic who worked for the ambulance service in Te Anau.

The organisation was relieved to learn the trio were safe and well and now receiving medical treatment.

"We are providing support to the family of our paramedic and to his St John colleagues. His family feel a huge relief and is looking forward to being reunited with their husband and father later tonight. They thank everyone for their interest and well wishes and ask for you to respect their privacy at this time."

Helicopter pilot Andrew Hefford was rescued from a remote beach after a helicopter crash in the Southern Ocean. Photo / supplied

Meanwhile, Lloyd Matheson says he might owe his colleague and good mate Lester Stevens at Southern Lakes Helicopters a beer.

Matheson, operations manager for the Te Anau company and also Aviation New Zealand president, was supposed to be the volunteer winch operator on the medevac helicopter mission last night that crashed near the Auckland Islands, 465km south of New Zealand.

But due to a funeral, he swapped places with Stevens at the last minute.

"I definitely have some mixed feelings about the whole situation, I was meant to be there but asked my mate to stand in for me," Matheson told the Herald.

The three crew on board were found walking on a beach just before 10am today by rescue teams that included Sir Richard "Hannibal" Hayes, the company's CEO and chief pilot.

"We are elated to hear they are safe, this is the best news, it is like 10 Christmases have come at once," said Matheson.

The last contact with the helicopter was at 7.37pm last night near Yule Island, at the northern end of the subantarctic island group.

Since that there had been no signals from the helicopter nor distress beacons issued.

Southern Lakes Helicopters informed the Rescue Coordination Centre NZ that its helicopter was missing at 8.15pm and a search operation commenced immediately.