Donald Trump's nominee to lead the FBI has pledged to insulate the agency from outside interference, amid a probe into Russian election interference that could threaten the president and his inner circle.
"If I am given the honour of leading this agency, I will never allow the FBI's work to be driven by anything other than the facts, the law, and the impartial pursuit of justice. Period," Christopher Wray told a Senate Judiciary Committee hearing on his nomination.
"There is only one right way to do this job, and that is with strict independence, by the book, playing it straight, faithful to the constitution, faithful to our laws, faithful to the best practices of the institution, without fear, without favouritism, and certainly without regard to any partisan political influence," he said.
Mr Trump fired the respected director of the Federal Bureau of Investigation James Comey in May, expressing frustration about the ongoing investigation into whether his presidential campaign colluded with an alleged Russian effort to tilt the election in his favour.
That raised allegations of obstruction of justice against the president and led to the appointment of an independent prosecutor, Robert Mueller, another former FBI chief, to oversee the Russia probe.
Senator Dianne Feinstein, the top Democrat on the judiciary panel, told Mr Wray he must be committed to pursuing any investigation to the end no matter who is implicated.
"The FBI director does not serve the president," Ms Feinstein told the hearing.
"He serves the constitution, the law and the American people. As such, the director of the FBI must be a leader who has the integrity and strength that will enable him to withstand any attempts at political interference."
Asked about his views on practices like waterboarding, inflicted by CIA and FBI interrogators on detainees in the years after the 9/11 terror attacks, Mr Wray said he did not support them.
"My view is that torture is wrong, it's unacceptable, it's illegal, and I think it's ineffective," he said.
He also said that he considered waterboarding, one of the most notorious interrogation techniques, to be "torture".
Mr Trump spoke positively about torture during last year's presidential election campaign, suggesting he would bring back waterboarding.
But since his election, he has said he would follow the advice of his top aides including Defense Secretary Jim Mattis, who opposes the practice.
Mr Trump's Attorney General, Jeff Sessions, said in his confirmation hearing in January that he recognises the 2015 law passed by Congress that outlaws waterboarding and other forms of torture, a law he opposed when he was in the Senate.
Mr Wray's role as a Justice Department assistant attorney general managing the criminal division in 2003-2005 raised questions over his handling of allegations of torture at the notorious US-run Abu Ghraib prison in Iraq.
According to government documents published online by the American Civil Liberties Union, his name is mentioned in several communications at the time on torture cases.
Mr Wray told the Senate hearing that at the time his office had opened a number of torture investigations based on reports they had received, most of which would have been resolved after he left the department.
But he said he was "proud" of his role in prosecuting a US contractor for the Central Intelligence Agency for torture that killed an Afghan detainee in 2003.
