WASHINGTON, Dec. 9  -- The Central Intelligence Agency (CIA) repeatedly misled the public, Congress and the White House about its aggressive questioning and torture on detainees after the Sept. 11, 2001 terrorist attacks, according to a U.S. Senate report released here Tuesday.

The CIA downplayed the brutality of the interrogations and exaggerated the usefulness of the information it gathered, including its role in setting in motion the U.S. raid that killed al-Qaeda leader Osama bin Laden, said the Senate Intelligence Committee report.

The 6,000-page report also found that the "Enhanced Interrogation Techniques" program escaped effective scrutiny by outsiders long after its inception in 2002, with CIA records showing then President George W. Bush was never fully briefed by the agency on torturous interrogation techniques until 2006.

The report contained details about waterboarding, sexual threats and other controversial methods to obtain information, finding those techniques were largely ineffective and poorly managed.

Some of the detainees were kept awake for up to 180 hours, or more than seven days, usually in standing or stress positions. Interrogators also placed the interrogations above medical needs, such as treating bullet wounds, the report said. Some detainees were also placed in ice water "baths".

According to the report, interrogators told several detainees they would never be allowed to leave alive, and told one he would never go to court because "we can never let the world know what I have done to you."

Conditions at CIA detention sites were poor, the report pointed out, saying detainees at a detention facility called "COBALT" were kept in complete darkness, and lack of heat at the facility likely contributed to the death of a detainee.

The prisoners were also subjected to "rough takedowns," where approximately five CIA officers would scream at a detainee, drag him outside of his cell, cut his clothes off and secure him with Mylar tape. The detainee would then be hooded and dragged up and down a long corridor while being slapped and punched, the report said.

The White House and U.S. President Barack Obama backed the decision to release the report, despite warning from lawmakers and some officials inside the administration that it could lead to a backlash against Americans.

Obama said in a written statement after the report's release that Bush-era CIA interrogation techniques "did significant damage to America's standing in the world and made it harder to pursue our interests with allies and partners."

While the United States "did many things right" in the years after the Sept. 11 terror attacks, Obama said "some of the actions that were taken were contrary to our values." That's why he " unequivocally banned torture" upon taking office in 2009, the President noted.

"These harsh methods were not only inconsistent with our values as nation, they did not serve our broader counterterrorism efforts or our national security interests," Obama said.

"Moreover, these techniques did significant damage to America's standing in the world and made it harder to pursue our interests with allies and partners," he said, adding "that is why I will continue to use my authority as president to make sure we never resort to those methods again."

On Monday, White House spokesman Josh Earnest said at a press conference that "prudent steps" have been taken to boost security at U.S. facilities in the event of violent protests. The White House supports the release of the report, he said, adding things like the use of torture "should never happen again."

But former Vice President Dick Cheney defended the agency's actions, saying he never believed the CIA withheld information from the Bush administration, and that the program had been authorized by the Justice Department, according to an interview by the New York Times with Cheney.

The former vice president, one of the program's strongest supporters, said the CIA officers who ran the program should be " decorated, not criticized."

CIA Director John Brennan also defended the agency from the report's criticisms while acknowledging that the spy agency "made mistakes" in previous years.

Information learned through the interrogations was "critical" to understanding terror group al-Qaeda, he said, while rejecting the notion that officials "systematically and intentionally" misled Congress, the White House and the American public.

Meanwhile, former CIA director Michael Hayden denied that the CIA lied about its program. He said releasing the report will make it less likely that countries that cooperated in the past with Washington on the War on Terror will do so in the future.

The long-delayed report took five years to produce and is based on more than six million internal agency documents of CIA. U.S. military commanders and embassies worldwide have been bracing for possible fallout and security threats due to sensitive information in the report.