U.S. Attorney General Eric Holder is considering whether to appoint a criminal prosecutor to investigate the Bush administration’s interrogation practices involving the CIA, and is expected to make a decision in a few weeks, a Justice Department official said on Sunday.

The official, who declined to be identified, said any investigation would only cover those who went beyond the Justice Department’s legal advice at the time that authorized various harsh interrogation techniques.

Republican senator and former presidential candidate John McCain criticized the idea, but a leading Democratic senator and civil rights group expressed support.

Central Intelligence Agency employees who acted in accordance with the Justice Department’s approved methods at the time would not be investigated, the source said on condition of anonymity.

This was the position the Obama administration announced in April when it released Justice Department memos from the Bush era that had authorized waterboarding and other coercive methods of interrogation of terrorism suspects.

The official described Holder as “very reluctant” to open the investigation but said the attorney general could be forced to do it because of the “nature of the conduct” at issue.

Justice Department spokesman Matthew Miller said Holder will “follow the facts and the law.”

“We have made no decisions on investigations or prosecutions, including whether to appoint a prosecutor to conduct further inquiry,” Miller said. “As the attorney general has made clear, it would be unfair to prosecute any official who acted in good faith based on legal guidance from the Justice Department.”

When asked on the “Meet the Press” television program if the investigation is a good idea, former presidential candidate and torture survivor Senator John McCain, simply said “No.”

“We all know that the operatives who did it most likely were under orders to do so,” he said, adding that “airing out and ventilating details” would harm the country’s reputation.

Also speaking on “Meet the Press,” Senator Charles Schumer said he agreed with President Barack Obama’s contention the United States should be “looking forward, not backward.”

“But when there are egregious violations, you can’t just brush them under the rug,” said Schumer, who sits on the Senate’s Judiciary Committee. Holder’s scrutiny of the interrogations is “the right thing to do.”

Formed in 1947, the CIA gathers information on foreign governments and individuals but holds no policing powers.

“A criminal investigation is clearly warranted,” said the American Civil Liberties Union in a statement.

The group recently received a redacted version of a CIA inspector general’s report on the interrogation techniques and is pressing for a more complete version to be released.