WASHINGTON — The Justice Department in 2002 told the CIA that its interrogators would be safe from prosecution for violations of anti-torture laws if they believed “in good faith” that harsh techniques used to break the will of prisoners, including waterboarding, would not cause “prolonged mental harm.”

The newly released but heavily censored memo approved the CIA’s harsh interrogation techniques method by method, but warned that if the circumstances changed, interrogators could be running afoul of anti-torture laws.

The August 1, 2002, memo signed by then-Assistant Attorney General Jay Bybee was issued the same day he wrote a memo for then-White House Counsel Alberto Gonzales defining torture as only those “extreme acts” that cause pain similar in intensity to that caused by death or organ failure. That memo was later rescinded by the Justice Department.

Waterboarding is a form of simulated drowning that critics call torture. CIA Director Michael Hayden banned waterboarding in 2006 but government officials have said it remains a possibility if approved by the attorney general, the CIA chief, and the president.

The Bush administration memos authorizing interrogation techniques have been leaked to the press and released under the Freedom of Information Act starting in 2004, when the Abu Ghraib prison abuse scandal uncovered detainee mistreatment. Today’s release adds to the growing record of the still secret program launched after the September 11 terrorist attacks.

The new Bybee memo was obtained by the American Civil Liberties Union, along with two other previously unreleased documents dealing with the CIA’s interrogation program. The Bybee memo specifically approved proposed interrogation techniques that were devised for use against Al Qaeda suspects who were resistant to traditional questioning methods.