Two leading human rights groups on Monday called for U.S. Attorney General Eric Holder to appoint a "special prosecutor for torture" to investigate violations of criminal laws relating to the CIA's use of torture techniques.

In light of new information disclosed in the recent Senate Intelligence Committee report on the CIA torture program between 2002 and 2007, Human Rights Watch and the American Civil Liberties Union wrote a letter to Holder asking for a new investigation.

The prosecutor should be provided "with files from the investigation completed by John Durham and his investigators, as well as the full 6,700-page version of the Senate torture report," and should be asked to "conduct a comprehensive criminal investigation of the conduct described in the report, including all acts authorizing or ordering that conduct," the letter said.

The White House has repeatedly refused to further investigate into the matter, instead pointing to a previous investigation conducted by a special prosecutor, Durham, who spent three years looking into possible wrongdoing by the CIA and determined that the "admissible evidence would not be sufficient to obtain and sustain a conviction beyond a reasonable doubt."

But the two human rights groups claim the release of the new Senate report warrants a new investigation.

"There is a qualitative difference between having access to more than six million pages of documents," as Durham did, and "conducting a criminal investigation based on a 6,700-page report that pieces together those documents into a narrative indicating a vast criminal conspiracy, under color of law, to commit torture and other serious crimes."

Even if the former prosecutor's mandate was broad, "we have been unable to find any evidence that Mr. Durham or his investigators interviewed any prisoner who was subjected" to the CIA program, the letter said.

Citing an obligation under a United Nations covenant, the groups conclude, "The necessity of investigating issues of criminal liability is made more urgent by the fact that many of the individuals who authorized the conduct documented in the Senate torture report are publicly defending the necessity, effectiveness, and legality of that conduct. Against this background, 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 the rule of law at home."