The 53-page report claims that a number of Arab countries, including Saudi Arabia, Kuwait, and Syria, as well as the United States and Sweden, have all joined in this practice. And it refers to Egypt as the world's main recipient of detainees, including those who might have intelligence information useful in the war on terror.
Human Rights Watch cites estimates by Egyptian rights activists that up to 200 detainees have been sent to Egypt from various countries since the terrorist attacks against the United States on 11 September 2001.
Most of the detainees were suspected Egyptian militants who fled their homeland amid a government crackdown in the 1980s.
The report says the United States has been "particularly interested" in intelligence from Egyptian nationals, because of their possible links to senior Al-Qaeda terror figures.
Human Rights Watch expert Vanessa Saenen says the likely fate of returnees is well known, adding that the United States itself must know how bad the situation is.
"The State Department of the U.S. came out with its latest human rights report on Egypt, in February, which says -- and I quote -- 'torture and abuse of detainees by police, by security personnel and by prison guards remains common and persistent in Egypt,'" Saenen said.
She calls on all countries who have been sending suspects back to Egypt to end the practice.
"First of all, Egypt should immediately stop the torturing and the abuses in prisons, and uphold its own responsibilities under its own national law and international law; secondly, we believe that no country -- whether the United States, Sweden or the others -- should send back people to Egypt, a country where they know prisoners will probably be tortured," Saenen said.
The U.S. State Department on 6 May issued its own lengthy report in which it says the United States is "abiding by global anti-torture rules."
The report dismisses assertions that the United States is in any way involved in systematic torture.
And it says that when individual allegations of misconduct by U.S. personnel arise, these are investigated, and if substantiated, are prosecuted. The report has been submitted to the UN Committee Against Torture.
The London-based rights organization Amnesty International however is critical of the report, saying it minimalizes the allegations against the United States.
Amnesty official Rob Freer says the report does not address the activities of the U.S. Central Intelligence Agency (CIA).
"The activities of the Central Intelligence Agency remain to this day shrouded in secrecy, and that agency is implicated in many allegations of abuse in the war on terror, one of which is the alleged transfer of detainees between countries," Freer said.
Meanwhile, some Czech parliamentary deputies are seeking a debate in the Czech parliament on allegations that an airliner operated by the CIA and carrying detainees from Afghanistan to the U.S. made a refueling stop in Prague last week.
Czech Interior Minister Frantisek Bublin said he has no information that would either confirm or deny the allegations. But he said he had ordered officials to investigate whether the Czech Republic was in any way involved in such flights, and he said it is not.
Analysis: The Dilemma Of Torturing Terrorists