The first item Opus Dei gave 12-year-old Andrea Martínez was a pink dress. The second was a schedule that detailed every task for every minute of her day. Then, when she was 16, she was given a cilice – a spiked metal chain to wear around her thigh – and a whip.

In the late 1980s, Opus Dei, a secretive and ultra-conservative Catholic organisation, promised Martínez an escape from a life of poverty in rural Argentina. By attending one of their schools, they said, she would receive an education and opportunities.

“They told me I would study and progress. I thought with an education that later I would be able to help my family,” says Martínez, 50.

“But I became like a slave. They treated me like a slave, without any capacity to think or act or do.”