The Daily Mail quoted a Downing Street spokesman, as saying, "We stand firmly against torture and the cruel, inhumane or degrading treatment or punishment. We don't condone it or ask others to do it on our behalf."
Meanwhile, lawyers have warned that by having sanctioned the controversial interrogation technique, he could now be arrested for breaking international law if he travels abroad.
"Ignorance of the law is no defence. There are countries where proceedings might be instituted against him," human rights lawyer Geoffrey Robertson said.
Bush made this comments during an interview while launching his memoir "Decision Points", admitting that he gave the CIA the green light to waterboard Khalid Sheikh Mohammed, the mastermind of the 9/11 attacks. He added that a team of U.S. lawyers had said the practice was not illegal.
However, his claims about waterboarding were dismissed by a series of senior officials familiar with counter-terrorism activities at the time, saying that the President was exaggerating.
Kim Howells, who was chairman of the Commons intelligence and security committee, said: "I doubt torture actually produced information which was instrumental in preventing those plots coming to fruition. I'm not convinced of that."
However, security sources said that information passed by the US in the years after 9/11 did help prevent some Al Qaeda attacks in the UK.
In a speech last year MI5 director general Jonathan Evans had said that 'such intelligence was of the utmost importance to the safety and security of the UK. It has saved British lives.' He further claimed that Bush was prepared to approve waterboarding but there was a longer list of proposed techniquesm, adding: "There were two that I felt went too far, even if they were legal."
Last year, U.S. Justice Department memos had revealed that the CIA had waterboarded Khalid Sheikh Mohammed 183 times in March 2003, and fellow Al Qaeda commander Abu Zubayda at least 83 times in August 2002, the paper said.