As told by Chris Albin-Lackey, senior researcher for the Business and Human Rights division

We parked our land cruiser by the side of the dirt road, high in the mountains covered with lush, green vegetation. In the distance, framed by greenery, was a vast, flattened plateau, a gold mine owned by Canada-based Barrick Gold. Next to the mine were the waste rock dumps – the scene of the alleged crime. Even from afar, we could see the illegal miners on the gray rocks.

I sat on a bench in the back of the truck across from Mary, a short, heavy-set woman with cropped curly black hair. She seemed to be in her late 30s, and her teeth were stained from beetlenuts, a mild stimulant chewed by most people in Papua New Guinea. She was trying not to cry.

She had been standing on the waste dump, she said, selling bags of beetlenuts to the illegal miners panning for gold when the cars carrying Barrick’s security guards pulled up. They leapt from the cars and began sprinting toward the people working on the dump. Everyone ran. But Mary, fumbling with her wares, tripped and fell on the rocks. The guards caught her, and brought her back to one of the cars.

The guards taunted her and told her she would either go to prison or pay a massive fine for mining illegally. Then they asked her if she wanted to go to prison or if she wanted to go home.

Mary had heard what happened to women who were caught on the waste dump, and she believed the guards were asking her a question: Would she rather go to prison or let all five guards rape her in return for letting her go?

Mary said prison. Barrick’s guards didn’t listen.

Barrick, valued at $47.6 billion, is the world’s leading gold producer. Since the Papua New Guinea Porgera Joint venture mine opened in 1990, the mine has produced more than 16 million ounces of gold. At today’s prices, that would be worth more than $20 billion. Barrick took over the mine in 2006 , and production is expected to continue until at least 2023.

While rumors of abuses like gang rapes and beatings had long been associated with the mine, Barrick Gold – the world’s largest gold mining company in terms of production – had denied these claims as unfounded.

But when we went and investigated these abuses, allegedly committed by the mine’s private security staff, we found information corroborating the allegations.

While Mary told me the details of the gang rape, she often had to stop and collect herself. During these moments, I’d look out the window or at the floor.

Whenever I interview a woman who has been raped, I wonder if it would be easier if I were also a woman. I’m not sure. In these situations, I always have a good female translator with me. I tend to take things more slowly and quietly, giving the woman space to tell her story – or not tell it, if that’s what she wants. It’s extremely difficult and uncomfortable no matter who you are.

In short, the five guards ignored her plea and did what they wanted. They punched and kicked her while they raped her. Then they left her badly hurt, lying on the rocks, still on Barrick’s property. With the help of a stranger, she limped home – a long walk, mostly uphill.

Mary’s story stuck with me not only because her alleged rape by Barrick’s guards was so terrible, but because what happened next was even worse. People in her community either saw what happened to her or guessed. Neighbors taunted her, and her husband left her, saying he didn’t want to “be with her anymore after these five men had their chance with her.” Within a few days, she was totally ostracized and very alone.

Before taking our information public, we showed our findings to Barrick during an all-day meeting in their Toronto headquarters. When confronted with our research, Barrick acknowledged for the first time that the allegations had substance and it has since taken steps to rein in the alleged abuses we uncovered. Barrick opened an internal investigation at the mine in Porgera, which echoed and confirmed our findings. The police also opened an investigation.

Days before we released our findings publicly, Barrick announced that the police had arrested several security guards accused of sexual assault and other serious crimes – although none are accused of Mary's rape. (Neither Mary, nor the other women we interviewed, have so far chosen to come forward.)Meanwhile, the company has promised to establish more effective channels for community members to complain about abuses without fear of retaliation. Barrick has also promised to improve oversight of senior security personnel.

I saw Mary again five or six months later. It was remarkable how much her life had changed since I last saw her. She was funny and gregarious. She had remarried, and her new husband knew about what had happened and was sympathetic and understanding. She was getting follow-up treatment at a hospital and getting tested for HIV.

She was, it seemed, finally bouncing back.