They spent their days on the work site and at night they slept in a large company house, which was under 24-hour guard by security officers and surrounded by razor wire — a pretty standard arrangement for foreign workers in the crime-ridden city.

Jenkins told news.com.au about 4am one night, towards the end of his time in Port Moresby, his brother barged into his bedroom holding two knives to defend themselves.

"He said some guys were trying to come into the house and he had heard one of the guards screaming," Jenkins said.

"And then I looked out my window and saw both of our guards tied up, kind of hog-tied, about two metres away from me.

"I saw these other guys standing over them and I could hear people trying to get up the side of the house. And then I got a message from my boss, who lived upstairs, saying, 'Whatever you do, don't go outside'."

Jenkins said the men were most likely trying to rob the house, which had already been targeted by thieves about four times that year.

He and his brother cowered in a room while the madness unfolded outside.

"We were sitting in the corner with these knives — I mean, we were probably not going to use them if they came in, I don't know what would have happened," Jenkins said.

"Then one of the guards got free somehow and radioed through to some other guards. All these crews showed up in these trucks, with German shepherds — about 20 other guards came. And then we heard all these gunshots. And we were sitting in this corner, just freaking out."

Jenkins said after a shootout, the guards managed to drive the would-be robbers away and he and his brother eventually stepped outside.

"The guards were all bloodied and had ripped shirts and looked like they'd been bashed," he said.

"They said there were about eight guys who were trying to get in. I don't know what they were going to do, but it was pretty scary.

"I put something up on Facebook [about it] and started getting messages from my mum and friends, saying it wasn't worth the money and to get out of there. We left. I don't think I'll go back."

Jenkins' work had previously taken him around Australia, as well as to Canada and the UK, but Port Moresby was very different.

He already had a sense of the danger there — earlier, he'd had the unpleasant experience of someone snatching at his phone through the window while he was in a slow-moving car.

"My boss had told me about 80% of [people in Port Moresby] were friendly but there's a big 20 per cent who, when they see you're a white person, will do what they can to rob you or kidnap you or hold you hostage," he said. "Some people are so poor, they'll do anything."

Port Moresby's high crime rates, poor security, police corruption and civil unrest makes it the most at-risk destination for Australian business travellers, according to a new report by American Express Global Business Travel and travel risk management experts iJET International.

The Department of Foreign Affairs and Trade says Australian officials in Papua New Guinea "adopt heightened security measures while travelling, at home, at work and in public places", due to the country's high level of crime. Australians are urged to exercise a high degree of caution in the country.