Bikram Yoga Decatur

"South African prisoners embrace yoga"

Mrs Khoosal says she has seen a change in the prisoners in just the seven days since she first met them.

"They thought it was an Indian thing, and heckled us, but by the end I could feel they weren't just doing it for the certificate."

The yoga technique she teaches can control emotions, she says.

"When we are angry we breath a certain way and when we are sad we breath another.

"If you can control the breathing, you can therefore control the emotion."

The inmates weren't the only ones who were sceptical.

"When I first heard about it I thought: 'How can that help?'" Anita Hanekom, head of Social Services at the prison told the BBC.

"But now I've seen it can work."