Kiwi journalist Glen Johnson witnessed horrific beatings and even tried to intervene in one attack while he was investigating a people-smuggling ring taking Africans into the Middle East.

Speaking for the first time about the circumstances that led to his arrest in Yemen, and imprisonment for a fortnight, Johnson told the Herald on Sunday he was captured by police after being led into the desert at gunpoint. He had joined the smugglers on a boat ride from the eastern African state of Djibouti, 35km across the Gulf of Aden. The smugglers reneged on a deal to take him back to Africa and instead gave him to Yemeni officials.

He was one of about 50 people, mainly Somalians and Ethiopians, on a small fishing boat to Yemen, and was transported in a truck from the coast to a camp in the Yemeni desert, a staging post before another land trip for refugees looking for a better life in Saudi Arabia.

It was at the camp Johnson, freed just over a week ago and now in Cairo, Egypt, saw smugglers commit atrocities on those they had been paid to take out of Africa.

"I saw around 60 people beaten, at times very severely," Johnson said. "There was one instance of what I would consider sexual assault, perhaps forced prostitution - which is the same thing."

The smugglers beat the refugees, looking for more money and even making cellphone calls for them to arrange more cash. The beating of one Ethiopian woman was too much for Johnson, 28, to bear.

"She had given me a pair of Jandals in the morning - I was a mess from sleeping in a bloody ditch, covered in several hundred ant bites: dirty, stinking. While she was being beaten, I decided to intervene - the beatings had been going on for hours by that stage. All day there were screams and wails and the traffickers yelling.

"I walked down into the camp carrying her Jandals, walked up to her - it was bizarre, everyone stopped and stared at me, all bug-eyed - I handed her Jandals to her, and she sort of pulled them into her stomach, and I said 'thank you so much' and then walked off. And the beating continued. It was a moment of absurd cowardice. In the end, it made no difference."

Johnson said he spent 30 hours on the perimeter of the camp before being handed over to the Yemenis.

"I was put in a truck and driven out into the desert somewhere near Kharaz refugee camp. I was told to get out of the vehicle with a guard who told me to walk off the road and then to sit down. I didn't have a clue what was going on - but it crossed my mind that he might shoot me. We waited maybe five minutes before a police car showed up. I was bundled into the back of the vehicle and driven to the police station at a nearby refugee camp."

The smugglers, who he had paid US$500 to take him into Yemen and back to Djibouti, took all of his money and bank cards, but bizarrely left him with his laptop.

"Seemingly, even traffickers respect the press to the extent where they won't touch our equipment."

Johnson said he had not intended to be among the refugees transiting in Yemen, but "something went wrong". "The smugglers in Djibouti are much more approachable than in Yemen.

"Yemen is perched on the brink of a fractious conflict that could escalate dramatically. My plan was to see the boat trip and get back to Djibouti as quickly as possible. That didn't happen."

Johnson said he had no idea what happened to the refugees looking for a better life in the Middle East, but he didn't hold out much hope for those without access to money. They had had to front with up to US$200 to get on the boat. While in prison, a guard told him there were 100 Ethiopians in another cell, refugees caught by police.

"I assume that the people at the staging post who couldn't come up with more money were driven into the desert, similar to me, and their locations disclosed to the police."

Johnson thought there was little chance of the situation improving or of refugees being blocked legitimately at the border.

"It is a very lucrative trade and the blowback from the tribes and people profiting - with probably little other way of supporting themselves, if the Government did manage to stamp it out could be severe."