U.N. human rights investigators, citing "persistent and credible" reports of torture at the U.S. base in Guantanamo Bay (search), urged the United States on Thursday to allow them to check conditions there.
The failure of the United States to respond to requests since early 2002 is leading the experts to conclude Washington has something to hide at the Cuban base, said Manfred Nowak, a specialist on torture and a professor of human rights law in Vienna, Austria.
"At a certain point, you have to take well-founded allegations as proven in the absence of a clear explanation by the government," Nowak said.
However, he added: "We are not making a judgment if torture or treatment under degrading conditions has taken place."
Washington's response is delayed because the U.S. review process is "thorough and independent" and involves the Bush administration, Congress and the judicial system, said Brooks Robinson, spokeswoman for the U.S. mission to U.N. offices in Geneva.
"The main point is that their request is being addressed and discussed and reviewed in the United States," Robinson told The Associated Press. "That process is underway."
But one investigator, Algerian magistrate Leila Zerrougui, said: "The time is up. We have to act now. If not, we won't have any credibility left."
For more than three years, U.N. investigators have made numerous requests to visit foreign terror suspects at the U.S. Naval base in Cuba and at U.S. facilities in Iraq, Afghanistan and elsewhere, the four independent specialists told reporters.
"We deeply regret that the government of the United States has still not invited us to visit those persons arrested, detained or tried on grounds of alleged terrorism or other violations," the experts said.
The four, who report to U.N. bodies on different human rights issues, are appointed to their three-year terms by the 53-nation U.N. Human Rights Commission (search), the global body's top rights watchdog. They are unpaid for their work, although their expenses are paid.
The United States has criticized the commission because its members include countries with tyrannical governments and poor human rights records, but the experts operate autonomously, often reproaching their own countries and others in the commission.
The four cited "information, from reliable sources, of serious allegations of torture, cruel, inhuman and degrading treatment of detainees, arbitrary detention, violations of their right to health and their due process rights.
"Many of these allegations have come to light through declassified (U.S.) government documents," the statement said.
U.S. officials have consistently denied violating the principle of humane treatment of detainees in the war on terror, and Robinson noted that American policy "prohibits and condemns torture."
"American personnel are required to follow this policy and applicable law," she said. "Credible allegations of illegal conduct by U.S. personnel are taken seriously and investigated."
The specialists said they had yet to hear back from Washington on their latest request — made a year ago and renewed in mid-April — to visit the detention facility.
In an April meeting, U.S. officials refused to guarantee the right to speak to detainees in private — an "absolute precondition" for such a visit, Nowak said.
Paul Hunt, a law professor from New Zealand who monitors physical and mental health of detainees, said he wanted to investigate "persistent and credible reports" of alleged violations in person.
"Reportedly medical staff have assisted in the design of interrogation strategies, including sleep deprivation and other coercive interrogation methods," Hunt said.
The experts said they decided to express their misgivings because "the lack of a definitive answer despite repeated requests suggests that the United States is not willing to cooperate with the United Nations human rights machinery on this issue."
"We are all worried about this situation," said Argentinian jurist Leandro Despouy, specialist on the independence of judges and lawyers.
U.S. officials so far have allowed only the International Committee of the Red Cross (search) to visit detainees at Guantanamo, which started being used as a detention center for terror suspects allegedly linked to the Taliban (search) and Al Qaeda (search) after the U.S.-led invasion of Afghanistan in late 2001.
The ICRC keeps its findings confidential, reporting them solely to the detaining power, although some of the reports have been leaked by what the ICRC terms third parties.
The U.N. experts would be expected to make a public report.
Nowak worked in the 1990s as U.N.-appointed expert on missing persons in the former Yugoslavia. He also has served as a judge at the Human Rights Chamber for Bosnia and Herzegovina in Sarajevo.
As a U.N. expert on arbitrary detention, Zerrougui has previously criticized China for its policies in Tibet, Nepal for its treatment of journalists and others, and Russia for its anti-terrorism measures.
Hunt has been in his post since 2002. Before that, he reported to the U.N. as a special expert on human rights and poverty issues.
Despouy is a former Argentinian ambassador to the U.N. in Geneva who chaired the Human Rights Commission in 2001. He also served as a U.N. expert on extreme poverty in the 1990s.