Spotlight: FBI chief defends revealing Clinton probe while staying quiet on Trump one before U.S. elections

FBI Director James Comey on Wednesday defended his decision to announce a new investigation into Democratic presidential candidate Hillary Clinton's emails while staying quiet on the Trump-Russia one prior to the 2016 U.S. elections.

Sending the letter to Congress about the Clinton probe less than two weeks before the elections was "one of the world's most painful experiences," Comey told U.S. lawmakers, saying he was facing a hard choice between "really bad or catastrophic" actions and he couldn't conceal.

"Concealment in my view would have been catastrophic, not just to the FBI but well beyond," he said.

Comey made remarks when testifying before the U.S. bipartisan Senate Judiciary Committee hearing on the probes into both Hillary Clinton's use of a private email server and the accused Russian meddling in the presidential election.

He also said he felt "mildly nauseous" to think he affected the final results of elections, as Clinton and many Democrats believe, arguing that politics can't influence the FBI's decision-making.

"It was a hard choice" but he had no other option, said Comey, "I couldn't conceal that."

During the hearing, the FBI chief was repeatedly grilled by lawmakers asking him why he revealed the Clinton investigation, but stayed quiet about the Trump-Russia probe during the campaign.

"Was it appropriate for you to comment on one investigation repeatedly and not say anything about the other?" Democratic Senator Patrick Leahy asked.

"I think so," Comey replied.

The FBI chief insisted he treated investigations into both Trump and Clinton "consistently under the same principles" and suggested that will continue to be the case.

He told lawmakers he has "high confidence" about the Russian hacking into the Democratic National Committee's email system, but there won't be another "peep" about the Trump-Russia investigation until it is done. The Russian government has denied all concerned accusations repeatedly.

"With respect to the Russia investigation, we treated it like we did with the Clinton investigation," Comey said. "We didn't say a word about it until months into it, and then the only thing we've confirmed so far about this is the same thing with the Clinton investigation: that we are investigating, and I would expect we're not gonna say another peep about it until we're done."

"A cloud of doubt hangs over the FBI's objectivity," Senate judiciary committee Chairman Chuck Grassley said in his opening remarks, "The public's faith in the FBI, Congress, and our democratic process has been tested lately."

Clinton on Tuesday said she was "on the way to winning until a combination of Jim Comey's letter on October 28 and Russian WikiLeaks raised doubts in the minds of people who were inclined to vote for me and got scared off."

"If the election had been on October 27, I would be your president," she said at a Women for Women event in New York.

Hours later after Clinton's remarks, Trump tweeted that Comey was "the best thing that ever happened to Hillary Clinton in that he gave her a free pass for many bad deeds!"

"The phony Trump/Russia story was an excuse used by the Democrats as justification for losing the election," said Trump on Tuesday night.

Comey announced in July that FBI was closing the Clinton email probe and he would not recommend charging Clinton or her aides. But less than two weeks before the election, he sent a letter to Congress announcing the FBI had found more emails pertinent to the investigation.

In March, Comey for the first time made public that the FBI had opened an investigation over the summer into accused Russian meddling in the presidential election and whether any Trump associates were involved. Endit