Director Lee Daniels had even offered to stop filming after fearing she had been hurt during the graphic action, reported Sun online.
But the 45-year-old Oscar-winning actress insisted to carry on and she needed make-up the next day to cover her bruises.
Co-star John Cusack, who plays a prisoner on Death Row, said that some shots were too explicit for the harrowing drama.
"There's a lot more scenes in there that was cut out, believe me. I was afraid I was hurting her, but she was more fearless than me.
"We shot the rough intimate scene on day one, and I barely knew her. Next day, Nicole showed up with bruises all over her legs," he said.