The New York Times
reported on Thursday that Eric Holder, the US attorney-general, and others in the justice department, favour the release in order to distance the present government from its predecessor.
The interrogation methods have been criticised by rights groups as torture, and both Holder himself and Leon Panetta, the director of the CIA, have said they consider waterboarding to be torture.
Panetta told US congress last week that the secret sites where CIA prisoners were waterboarded and interrogated by other harsh means were to be closed.
However, he said he had no intention of prosecuting any CIA employees for their role in a secret programme that was deemed legal at the time.
On Tuesday, a detainee at Guantanamo Bay told Al Jazeera in an exclusive interview that he had been continued to be mistreated since Obama came to power.
Mohammad al-Qurani told Al Jazeera's Sami al-Hajj, a journalist and former detainee, in a phone call from the facility that he had been beaten and tear gassed by guards and had been subjected to ill treatment "almost every day".
In an interview with Al Jazeera's Fault Lines programme, Richard Armitage, former deputy secretary of state under George Bush, said he would possibly have resigned had he known that detainees were being waterboarded.
"Torture is a matter of principle as far as I'm concerned. I hope, had I known about it at the time I was serving, I would've had the courage to resign," he said.
The CIA had admitted using waterboarding on three detainees at the Guantanamo Bay prison camp in Cuba, including Khalid Sheikh Mohammed, the suspected mastermind of the September 11, 2001, attacks in the US.
Obama ordered the Guantanamo prison camp closed within a year shortly after entering office and says the US will never again condone torture.
On Thursday, the New York Times also quoted US government officials as saying that the NSA had intercepted private emails and phone calls of US citizens beyond the limits set by US congress last year.
The agency also reportedly attempted in 2005 or 2006 to wiretap an unidentified US congressman while on a trip abroad without court permission, the paper said.
The US justice department told the Times that there had been issues with NSA surveillance operations but they had been resolved, while the NSA itself said its programmes were "in strict accordance with US laws and regulations".
However, intelligence officials said they were still investigating the extent of the NSA's practices and congressional investigators said they hope to determine if any violations of US citizens' privacy occurred, the paper said.