Rapper 50 CENT had to get completely naked for a prison shower scene in his movie debut GET RICH OR DIE TRYIN' when his flesh-coloured shorts changed colour under water.

50 was wearing the shorts to make sure his manhood was protected from view, but ripped them off when director Jim Sheridan explained they were hampering the scene, in which he's attacked by five inmates.

He explains, "We were supposed to shoot the scene above the waist and they had us put on these biker shorts that were exactly the same colour as our skin.

"When we went and got in the shower what happened was when the fabric gets wet, it gets darker and changes.

"Jim was like, 'This is not going to work.' And he said to me, 'You think you can take it (the biker shorts) off?' I was like, 'You gotta be kidding me, right?' But I did it."