When Australian nurse Christy King, 39, was employed as a trek leader on the remote Black Cat Track in Papua New Guinea, she thought it would be her dream job.

But within 24 hours she was faced with a moral dilemma of epic proportions when her group of 19 porters and eight Australian trekkers were ambushed and robbed at gunpoint by a group of bandits.

Two of the porters died after being savagely attacked with machetes and several others were left unable to walk with severe leg wounds.

While the trekkers' injuries were not life threatening, two had serious head wounds and two had nasty leg and arm injuries.

Speaking for the first time about her ordeal on Australian Story, Christy King said: "I knew I couldn't move them (the porters), I had to get help to them, that was heartbreaking having to leave them, a really tough decision."

Australian nurse Christy King, 39, was employed as a trek leader on the remote Black Cat track. ( Supplied )

This was the first time Christy King had worked for PNG Trekking Adventures as a trek leader, although she was an experienced bush walker in Papua New Guinea, having lived with her husband Daniel King as a resident in PNG's second biggest city of Lae for 10 years.

Ms King had walked the Black Cat track a number of times with her husband, friends and local guides and porters.

The Black Cat track runs from Wau, in the remote highlands of PNG, down to the coastal village of Salamoua.

Three of the Australian trekkers had already walked the popular Kokoda Track and were looking for a more extreme adventure.

"Once we were walking there was not a lot of talking going on so it was very peaceful. I was starting to realise this was really worth it. It was something I was starting to enjoy, just absorbing the place," Zoltan Maklary, the least experienced trekker of the group, said.

Terror on the Black Cat Track

While Ms King, the porters and trekkers were relaxing after a six-hour walk to their first camping spot, it is believed their attackers sat in the jungle, waiting for the rain to stop before ambushing the group.

Their first target was the porters, who were immediately rendered helpless by the violent attack.

A map showing the Black Cat Track in Papua New Guinea. ( Australian Story )

Ms King and the trekkers who were outside their tents, were made to lie on the ground.

Two of the trekkers who got out of their tents to see what was going on were savagely bashed on their heads with the butt of a firearm.

Trekker Pete Stevens looked up at one of the attackers and immediately had a trekking pole thrown at him which lodged in his leg.

Mr Maklary, who was in his tent listening to music with headphones on, said the first he knew of the attack was when his tent was ripped open with a machete.

Group unites to tackle moral dilemma

"It was a time freeze where they're either going to start on us or we're going to be OK. If we're OK, what am I going to do?" Ms King told Australian Story.

Australian trekkers on the Black Cat Track. ( Supplied )

"I knew that two of [the trekkers] had head injuries, they had trashed our camp, we had no shelter, potentially it was going to keep on raining, so what am I going to do?

"And at that stage in my head I had already thought: 'I will try and get... these people out'."

Ms King made the unenviable decision to walk the trekkers back to the safety of Wau where they could get medical attention.

They were also terrified at the idea of the attackers returning.

"At that point I discussed with her the really dangerous situation and [said] we probably should think about getting out of here. Were these guys going to come back?" trekker Rod Clarke said.

Fellow trekker, Mr Stevens, had a different view.

"I just said 'What are you doing?' and they said 'We're going. The decision has been made. We've got to go.' And I said 'No. We can't leave these people. We can't leave them'," Mr Stevens said.

Despite their different views, the group remained united and walked out together once they had attended to the porters' wounds and made sure they had food, water and shelter.

Some uninjured porters remained with their injured colleagues while they waited for help.

The group did not leave until they knew a rescue party was on its way.

"It's raining. It's in the jungle so it's pitch black. We were worried we were going to get ambushed ourselves going back on the track," trekker Jon Hill said.

Sorry, this video has expired The trekkers tell Australian Story of their brutal attack and the emergency rescue that followed.

Trekkers walk out while porters wait

As a former army officer, Mr Stevens warned the group they had to prepare to fight for their lives if the attackers returned, even though they were only armed with their trekking poles.

"I just said to the guys 'Look you know we've got to be prepared to fight if they come, we've got to work together and not go down one by one, we've got to fight back'."

Meanwhile, Daniel Hargreaves, a rescue leader and Wau resident, was leading a group of police and locals to the attack site.

"In PNG if there is a disaster you basically handle it yourself. You're your own law and order and emergency rescue," he said.

The rescue crew reached the porters about midnight.

Despite the thick jungle they were able to cut a helipad with their machetes and the porters were flown to Lae hospital at first light.

A legacy left behind: The Black Cat Porters Trust

On the hike out, the trekkers were already developing a plan to help the porters, knowing it would be unlikely they would receive adequate medical care in PNG.

A trust was established which has since been used to help the injured porters and the families of those killed.

Sorry, this video has expired Andrew arrives for surgery after attack

One of the injured porters, Andrew Natau, was flown to Melbourne at the end of January for specialist medical care at Cabrini Hospital.

He was greeted at the airport by the trekkers.

Mr Natau has since had three operations to repair severe tendon and nerve damage, and although he will never be able to walk like he did before the attack, his prospects are greatly improved.

While 10 men have been charged in PNG over the attack and are awaiting trial, Mr Natau said he does not hold any ill-feeling towards Ms King and the trekkers for leaving them on the mountain after the attack.

"I am not angry with you guys, you are from another country and we don't want you to die on our land," Mr Natau said.