WASHINGTON - President Obama should appoint a special prosecutor to determine whether former Bush administration and CIA officials broke the law by having suspected terrorists abducted and tortured in secret prisons by waterboarding and other brutal interrogation methods, two leading human rights groups said Monday.

The call by Human Rights Watch and Amnesty International was the second proposal for a special investigation issued from a human rights organization since the publication earlier this month of a blistering Senate Intelligence Committee report into the CIA interrogation program that ran from 2002 until 2007.

"We believe the failure to conduct a comprehensive criminal investigation would contribute to the notion that torture remains a permissible policy option for future administrations; undermine the ability of the United States to advocate for human rights abroad, and compromise Americans' faith in rule of law at home," Human Rights Watch and Amnesty International wrote in a joint letter to Obama.

The letter follows an analysis of the Senate report issued last week by Physicians for Human Rights, which urged Obama to appoint a special commission to examine whether CIA health professionals violated international and U.S. laws prohibiting experimentation on human subjects without their consent.

It's highly unlikely that Obama will embrace any calls for such investigations. The White House repeatedly has pointed out since the release of the Senate report that a special prosecutor who spent three years looking into possible wrongdoing by the CIA closed the probe in 2011 without finding sufficient "admissible evidence."

"The Department of Justice actually did conduct a review of the actions of CIA operatives that are mentioned in this report, that there was a career federal prosecutor who was assigned to this case and that this individual conducted an extensive inquiry, and upon looking at the facts in evidence decided not to pursue an indictment," White House spokesman Josh Earnest said on Dec. 10.

But Amnesty International and Human Rights Watch asserted in their letter that a fresh criminal investigation is warranted by new disclosures about the CIA program in the Senate report.

Even if the former special prosecutor, John Durham, had access to the more than six million pages of classified CIA cables, e-mails and other documents reviewed by the Senate investigators, the Senate report "has now synthesized a huge volume of information into a narrative that clarifies the extent and seriousness of criminal conduct," the groups said.

The United States, they wrote, is obliged as a signatory of international treaties banning torture to "effectively, independently, and impartially investigate all cases of unlawful killing, torture or other ill-treatment, arbitrary detention or enforced disappearance" and prosecute those found to be responsible, they wrote.

The Senate report, written by the majority Democrats, found that the CIA's use of waterboarding, which simulates drowning, extensive sleep deprivation and other interrogation techniques failed to produce any intelligence on imminent al-Qaeda attacks and that information gained from detainees was available from other sources.

CIA interrogators used methods that weren't approved as legal by the Justice Department and submitted detainees to medically unnecessary "rectal feeding" and "rectal rehydration," it said.