When Queensland carpenter Trent Jenkins agreed to go to Port Moresby for work, he knew he'd be helping to build a university.

What he didn't know was that a few weeks in, he'd find himself cowering in a room, metres from gunfire, with his temporary home under siege.

Jenkins, 32, has told of the horrifying experience he and his brother had in August while both were living and working in the Papua New Guinea capital, which has the dubious honour of being the most at-risk location for Australian business travellers.

The brothers, both carpenters, had been in Port Moresby for a month working with a large Australian construction company that operates in Papua New Guinea.

Jenkins said he knew Port Moresby could be
Jenkins said he knew Port Moresby could be "a bit gnarly" but nothing like the terrifying near-home invasion he experienced. Photo / News Ltd

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.

Riots break out on the streets of Port Moresby, Papua New Guinea in March 2017. Photo / AAP
Riots break out on the streets of Port Moresby, Papua New Guinea in March 2017. Photo / AAP

"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 tying 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 per cent 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."

Shanty houses are seen in the suburb of Erima in Port Moresby, Papua New Guinea. Erima is home to many of the city's Raskol gangs. Photo / AAP
Shanty houses are seen in the suburb of Erima in Port Moresby, Papua New Guinea. Erima is home to many of the city's Raskol gangs. Photo / AAP

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 joint report, called the Business Travel Alert Map, assesses cities were Australians frequently travel for work based on intelligence from risk analysts.

It named the second most risky city to be Rio de Janeiro, where business travellers risk public shootings and wandering into dangerous favelas.

Next is Johannesburg, where crime is concentrated in central business districts and business travellers are often targeted in "follow robberies" from airports and shopping centres.

Dhaka comes in fourth, due to high crime and terror activity in Bangladesh, and Istanbul is fifth, largely due to terrorism and civil unrest.

Despite all this, travelling to these cities remains part of the job for Australian workers across a range of industries.

"Despite ongoing global unrest, business travel remains an essential revenue driver for companies. Recently, our research indicated that employees are reporting heightened anxiety when travelling, and that the number of destinations causing concern has also risen,"

Jo Sully, the vice president of American Express Global Business Travel for Australia and New Zealand, said.

"It's absolutely expected that companies fulfil their duty of care obligations by taking action to mitigate risk and provide employee support. Knowing where travellers are is expected, but the ability to communicate with them during travel disruptions and other crises is equally important."

The research also identifies traditionally "safe" cities that are seeing an increase in risk to Australian travellers, including London and Paris. Both cities have been targeted by terror attacks over recent years and Paris has also seen major labour protests that have affected business operations.

iJET International's chief operating officer John Rose said companies needed updated intelligence on security concerns for places their staff were visiting or working.

"The global environment is always shifting," he said. "Our analysis shows that many destinations, historically perceived as safe, are now quite risky.

"Modern duty of care requires around-the-clock intelligence, combined with the technology to locate and communicate with employees in need. This may include repatriating travellers caught up in serious civil unrest or proactively sending information to help manage periods of disruption."

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.