Fifty-four foreign governments assisted the CIA in a global campaign that included harsh interrogations of suspects, a rights advocacy group said Tuesday, as it pressed for greater accountability.
The report by Open Society Foundations marks the most comprehensive list of countries that helped the United States in what critics saw as excesses by then president George W. Bush's administration after the September 11, 2001 attacks.
Bush authorized "extraordinary rendition" -- the transferring of individuals without legal process -- to allow US and foreign intelligence agencies to interrogate alleged extremists outside the protections ensured on US soil.
The Open Society Foundations found evidence that 54 foreign governments supported the system by actions such as hosting CIA prisons, interrogating suspects, allowing airspace for secret flights or providing intelligence.
Many of the cases involve countries that have long fought Islamic militants on their home territory such as Afghanistan, Egypt, Pakistan and Saudi Arabia.
The report also listed close US allies such as Australia, Britain, Canada, Denmark, Finland, Germany, Ireland, Italy, Poland, Spain, Sweden, Turkey and Thailand.
South Africa was listed in part due to allegations the Pretoria government gave US intelligence the green light in 2003 to abduct Saud Memon, a Pakistani suspected in the slaying of Wall Street Journal reporter Daniel Pearl.
Memon died shortly after his release in Pakistan in 2007.
The study also listed Iran, saying that despite poor relations with the United States, Tehran indirectly handed over at least 10 suspects -- mostly Arabs -- to US custody via the Kabul government.
The report called for accountability both in the United States and overseas, saying there was "no doubt" that Bush administration officials authorized what it called human rights violations.
"By engaging in torture and other abuses associated with secret detention and extraordinary rendition, the US government violated domestic and international law, thereby diminishing its moral standing and eroding support for its counterterrorism efforts worldwide," the report said.
But it said that other nations also bore responsibility. Only Canada has apologized for its role, while three other countries -- Australia, Britain and Sweden -- have also offered compensation to individuals.
President Barack Obama ordered an end to harsh interrogations when he took office in 2009. But the Open Society Foundations criticized Obama for still allowing renditions if other countries promise to treat prisoners humanely.
The group named 136 individuals subjected to extraordinary detention and rendition. As the report focused on secret CIA operations, it did not cover the Pentagon's controversial detention of prisoners in Guantanamo Bay, Cuba.
The Central Intelligence Agency kept some prisoners in Guantanamo Bay and also secretly held detainees in Afghanistan, Lithuania, Morocco, Poland, Romania and Thailand, the report said.
In detention, some prisoners were thrown against fake walls, forced into stressful physical functions, involuntarily stripped naked and slapped, the report said.
Former CIA chief Michael Hayden has previously confirmed that the US interrogators subjected three men to waterboarding, a drowning simulation that rights advocates consider to be torture.
The US Senate committee on intelligence in December approved a 6,000-page report on the CIA tactics. While the contents are classified, Senator Dianne Feinstein, the committee's chairwoman, said that secret detention sites and harsh interrogation were "terrible mistakes."
The CIA declined comment on the report. Some lawmakers and intelligence professionals have vigorously defended "enhanced interrogation techniques" as necessary against a ruthless enemy.
Hayden, speaking at a think tank last month, recalled telling European ambassadors in 2007 when he was CIA director: "We're at war with Al-Qaeda and its affiliates, this war is global in scope, and my moral and legal responsibility is to take that fight to this enemy wherever they may be."
The Open Society Foundations were founded by George Soros, the billionaire liberal philanthropist.