EXPLICIT CONTENT WARNING: This story and the above video contains graphic content.
Rapper Mos Def has staged a harrowing protest over the treatment of terrorism suspects in Guantanamo Bay.
The America hip-hop star, real name Yasiin Bey, agreed to undergo the procedure, which is being used on inmates currently undergoing a hunger strike in the controversial detention centre in Cuba.
Guantanamo Bay inmates are force-fed under only certain conditions: If they refuse nine successive meals or if their body weight drops significantly, they are offered a twice-daily can of a nutritional supplement.
If they refuse that, guards shackle them into the chair by their arms, head and feet, and a nurse inserts the tube up the nose, down the back of the throat and into the stomach.
Organised by human rights charity Reprieve, Bey begins his treatment by changing into an orange jumpsuit and being chained to chair, before having a tube inserted into his nose.
The upsetting footage shows him fighting the nurses administering the procedure, screaming, shaking then pleading with them to stop.
He then breaks down in tears.
"I really didn't know what to expect," he said afterwards.
"The tube went in and the first part of it was not that bad, but then you get that burning and it starts to get unbearable - it felt like something was going into my brain. I really can't take it."
The makers of the video claim what was used on Bey was standard operating procedure for force-feeding prisoners hunger striking at Guantanamo Bay.
104 of the 166 prisoners in the US prison began a hunger strike in February in protest at the conditions.
More information on the procedure can be found here.
* Watch the video here (warning: explicit content).