A Pentagon report last year argued that President George W Bush was not bound by laws banning the use of torture, according to the Wall Street Journal.
The US has been criticised for its treatment of terror suspects
The document also argued that torturers acting under presidential orders could not be prosecuted, the paper said.
The report was written by military and civilian lawyers for US Defence Secretary Donald Rumsfeld.
It came after staff at Guantanamo Bay complained normal interrogation tactics were not eliciting enough information.
The document outlined why restrictions on torture under US laws and international treaties might be overcome by considerations for national security or legal technicalities, the newspaper reported.
The draft argued that because nothing was more important than "obtaining intelligence vital to the protection of untold thousands of American citizens" normal strictures on torture might not apply, according to the Journal.
The report contended that the president, as commander-in-chief, has the authority to approve almost any physical or psychological actions during interrogation, including torture, the newspaper reported.
It said it had reviewed a draft dated 6 March, 2003, and had not seen the full final report.
But people familiar with the final text said there were few substantial changes from the draft version, the Wall Street Journal added.
It is not known whether President George W Bush has ever seen the report.
The Bush administration has said it supports the Geneva Conventions and humane treatment for detainees.