Doctors from across the world have urged the US military to stop the forced feeding calling the procedure "degrading and unethical".
In a letter to medical journal The Lancet published on Friday, 263 doctors from Britain, Ireland, the United States, Germany, Australia, Italy and the Netherlands also appealed to the American Medical Association, which endorses a World Medical Association ban on the force feeding of patients.
The World Medical Association says a prisoner should not be forcibly fed if a doctor believes they are capable of "unimpaired and rational judgment" to refuse treatment.
Dr William Hopkins, a psychiatrist at Barnet Hospital in London and a signatory to the letter, said: "Doctors force-feeding prisoners at Guantanamo are acting as an arm of the military. It is degrading and unethical to do this to people in detention."
Since the US prison camp opened in January 2002, scores of prisoners accused of links to Afghanistan's ousted Taliban or the al-Qaida terrorist network have waged hunger strikes to protest their indefinite detentions.
"Doctors force-feeding prisoners at Guantanamo are acting as an arm of the military. It is degrading and unethical to do this to people in detention"
Dr William Hopkins,
Psychiatrist, Barnet Hospital, UK
Many of the 490 men currently at Guantanamo have been held for four years without charge.
Six detainees are currently on a hunger strike at the US prison camp, US military spokesman Leiutenant Colonol Jeremy Martin said on Friday.
Three are being forcibly fed through tubes inserted into their nostrils.
The feeding of hunger strikers is carried out in a "humane and compassionate manner", only when necessary and "through lawful clinical means", said Martin, based at Guantanamo, in an e-mailed response to Associated Press questions.
Asked if force feeding was being carried out to prevent negative publicity likely to accompany any death of a hunger striker, Martin said the US "values are inherent in what we do ... to preserve the life of a hunger striking detainee".
Martin said the US military uses the same feeding procedure adopted by US federal prisons.
US military spokeswoman Cynthia Smith said the matter of whether physicians employed at Guantanamo were members of the AMA, and so in breach of the organisation's code, was "a personal decision and not one monitored by the department".
Some countries have had a policy of nonintervention in hunger strikes, including Britain, which in 1981 allowed 10 Irish Republican Army prisoners to die.
Attorneys acting for some detainees allege the US military sought to end a hunger strike in January by taking aggressive measures, including the use of a special restraint chair and thicker feeding tubes that are repeatedly removed and reinserted.
Dr John Kalk, an endocrinologist and another signatory to the Lancet letter who worked with political prisoners on hunger strike in South Africa in the late 1980s, said doctors should never betray their patient's wishes.
The US says forced feeding is
"We would give our patients as much information as we could about their health - but we could never go against their will, "said Kalk, who now works in Derby, central England.
No detainees have died at the Guantanamo prison, Martin said. However, there have been more than 34 suicide attempts since the camp opened. One prisoner was left with brain damage.