Jack O'Connell has revealed he chose to bare all in Starred Up.
The former Skins star, who plays offender Eric in David Mackenzie's prison drama, goes full-frontal in a scene, where his character is being strangled while having a shower.
"I think I did have the option to wear a modesty part. Contractually, I don't know if there was a clause but I think I made the decision not to bother. Because of what the scene entailed and it was all very violent, I didn't want to compromise it at all," he said.
Jack admitted he had some trepidation before they started shooting the scene.
"I was a bit nervous beforehand, because it was winter in Belfast and we didn't have central heating. And with the shower, obviously with the steam issues, they couldn't have it that hot so I thought it might affect things down there," he explained.
"I thought, if it appears, then hopefully it's not the centrepiece of the scene. I was busy getting strangled, so to speak, so it kind of escaped my thinking."
The 23-year-old sometimes carried his troubled alter-ego with him, even when the cameras stopped rolling.
"I guess in some cases, probably yeah. I reckon it's always subconscious to me because I wouldn't consider myself a method actor in that respect and the jobs that I have done. You go through the emotional mill on everyone, it's an emotional line of work," he said.
"Thankfully, I was able to turn Eric off and switch off quite easily. If I was challenged even further as an actor in the future, it might be necessary to live in the role for a bit, because the criticism I get for my performances is that they weren't extreme enough."
:: Starred Up opens in cinemas on March 21.