Actor and rapper Mos Def appears in a film which human rights group Reprieve says shows him voluntarily undergoing the standard operating procedure for force-feeding prisoners on hunger strike at Guantanamo Bay.

 (REPRIEVE HANDOUT) - The human rights charity Reprieve released a film on Tuesday (July 9) which it says shows actor and rapper Mos Def undergoing a force-feeding procedure on camera as part of a campaign to help Guantanamo Bay hunger-strikers.

In the end Mos Def - or Yasiin Bey as he is now known - was unable to undergo the full procedure and was heard on the film pleading to "stop, please stop".

The 39-year-old said afterwards on the film: "I really didn't know what to expect. Then the tube went in, and the first part of it is not that bad but then you get this burning, I got this burning. And then it just starts to be unbearable. It feels like something was going into my brain and it started reaching the back of my throat and I really couldn't take it."

The film, directed by Bafta award-winning filmmaker Asif Kapadia, was made by the human rights organisation Reprieve as the US government comes under pressure to stop force-feeding Muslim detainees during the holy month of Ramadan.