Seven former heads of the CIA have urged President Barack Obama to end an inquiry into allegations of prisoner abuse.
In a letter to the President the seven argue that the inquiry will hamper intelligence operations and keep the Central Intelligence Agency in a state of "continuous jeopardy".
The US Attorney-General last month named a prosecutor to examine whether criminal charges should be filed against CIA interrogators or contractors for going beyond approved interrogation methods.
The alleged excesses include using a power drill and making death threats in order to scare detainees.
Cases 'already investigated' in Bush's time
The former CIA chiefs say that the cases have already been investigated under the Bush administration and that lawyers declined to prosecute all but one contractor.
"This approach will seriously damage the willingness of intelligence officers to take risks to protect the country," they say in the letter. "In our judgment, such risk-taking is vital to success in the long and difficult fight against terrorists who continue to threaten us."
The letter is signed by three CIA directors under President George W Bush - Michael Hayden, Porter Goss and George Tenet - as well as by John Deutch, James Woolsey, William Webster and James Schlesinger, who dates to the Nixon administration.
The White House declined to comment on the letter. President Obama has previously said that the matter is up to the Attorney-General.