CIA interrogators threatened to kill the children of a man suspected of participating in the Sept. 11 attacks, and allegedly tried to persuade a second terrorist suspect that his mother would be raped in front of him, according to a newly declassified report.

The U.S. Justice Department released the report on Monday afternoon. Among other things, it says one interrogator may have told Khalid Sheikh Mohammed that if another terrorist attack took place in the U.S., "We're going to kill your children."

The interrogator who who is alleged to have made the rape threat against a suspect's mother has denied that he said that.

The American Civil Liberties Union had launched a lawsuit that led to the report being declassified. Written in 2004, it looks at CIA treatment of detainees suspected of terrorism, following the Sept. 11, 2001 attacks.

On Monday, U.S. President Barack Obama also approved the creation of a new, White House-supervised interrogation unit, a move that will push his administration even further afield from the hawkish security policies of his predecessor.

The structure of the new unit would shift control of high-level interrogations away from the Central Intelligence Agency, the U.S. spy agency that typically took the lead -- and sometimes full control -- when questioning al Qaeda suspects during the George W. Bush administration years.

The president's deputy press secretary, Bill Burton, told reporters that the unit will include members from across the U.S. intelligence community, but will be led by an FBI official.

It will be based at the FBI headquarters in Washington, he said.

The CIA will have involvement in the new unit which will include "all these different elements under one group," Burton said.

Information about the new interrogation group -- known as HIG for short -- is expected to be released sometime on Monday. But early indications are that the HIG will follow the rules of the Army Field Manual, which would end the use of sleep deprivation and subjecting prisoners to loud music for long periods as approved tactics.

On Monday afternoon, an official from the U.S. Justice Department said that prosecutor John Durham has been selected to investigate CIA mistreatment of terror suspects. The official spoke on condition of anonymity because they weren't authorized to relay the decision.

Durham is currently investigating how videotapes of CIA interrogations came to be destroyed, and will now look into whether contractors or CIA staff violated laws in the way they dealt with suspects.

Earlier in the day, a U.S. intelligence official told The Associated Press that the CIA welcomed the creation of the new unit, as the agency did not want to be involved in the long-term detention of suspects.

On the campaign trail, Obama voiced his disapproval of the Bush-era interrogation policies, though he has since said he does not favour prosecuting officials from the previous administration for their involvement in alleged prisoner-abuse cases.

As Burton put it Monday, the president believes "we should be looking forward, not backward."

Meanwhile, Attorney General Eric Holder is staring down a report from the U.S. Justice Department's ethics office, which recommends doing the exact opposite.

The New York Times reported Monday that the Justice report reveals that investigators conducted mock executions -- violating U.S. anti-torture laws -- and once threatened a suspect with a power drill and gun.

A government official told The Associated Press that no decision has been made yet and that internal deliberations are ongoing.

On Monday, CIA Director Leon Panetta told agency employees in an e-mail that he intended "to stand up for those officers who did what their country asked and who followed the legal guidance they were given. That is the president's position, too."

Burton said the president has faith in Holder to handle the issue and that Obama believes the attorney general should be fully independent from the White House when making such decisions.

"He is ultimately going to make the decisions," Burton said.

Burton made his remarks while Obama and his family vacationed in Massachusetts.

Also Monday, the CIA inspector general will release a different report that details the Bush administration's handling of suspects and its interrogation methods.

That report will be made public Monday. A federal court judge ordered that the report be released, in response to a Freedom of Information Act lawsuit filed by the American Civil Liberties Union.

Holder reportedly reacted with disgust when he read the classified version of the same report earlier this year.

National security expert Harlan Ullman said that the report will be controversial to the public, but will contain few surprises.

"The way the United States dealt with prisoners and how they kept them in Guantanamo Bay was a scandal and a disaster and I'm afraid that this is not going to help things," he told CTV News Channel during an interview from Washington on Monday morning.

With files from The Associated Press