The FBI did not put Hillary Clinton under oath – or record what she said – when agents questioned her for 3-1/2 hours last Saturday, the agency's director told Congress on Thursday.

Swearing to tell the truth is a typical pre-game tactic for court proceedings but not for law enforcement interviews.

Still, one Republican House member was startled to learn from FBI chief James Comey that no one administered an oath to Clinton when she answered questions.

'Well, that's a problem,' Florida Rep. John Mica said when Comey told him Clinton never promised to be truthful.

TELL THE TRUTH!: FBI Director James Comey told a congressional panel on Thursday that Hillary Clinton's interview about her classified email scandal wasn't conducted under oath, but it's still a crime to lie to agents. He also said no recording of the interview was made

YOU CAN'T HANDLE THE TRUTH: Clinton spoke for 3-1/2 hours with agents who might have a hard time proving if she ever lied to them because there is no exact record or transcript of their discussion

'WELL, THAT'S A PROBLEM': Florida Rep. John Mica reacted when Comey told him Clinton never promised to be truthful in her interview

'It's 'still a crime to lie to us,' Comey assured him during more than four hours of testimony before the House Oversight and Government Reform Committee.

But without a transcript of what Clinton said, it would be difficult to prove her words were false.

Some Republicans have demanded to see a transcript of what Clinton said, as part of broader doubts about how the FBI handled what might have resulted in criminal prosecution for keeping classified files on a private and unsecured email server.

'The American people would like to see what Hillary Clinton said to the FBI,' Senate Majority Leader Mitch McConnell told reporters on Wednesday.

CLOSE-UP: Comey declared this week that he wouldn't recommend a criminal prosecution of Clinton for mixing classified and unclassified materials on the unsecured private email server in her home

The Hill reported that FBI's policy since at least 2006 has been to forego the chance to make recordings of subject interviews.

Except in rare circumstances, 'agents may not electronically record confessions or interviews, openly or surreptitiously' the FBI said in a 2006 memo.

The only record of Clinton's interview is likely to be a Form FD-302, an investigative analysis that summarizes what the former secretary of state told her inquisitors.

Comey said he has read the '302' from Saturday's interview, and acknowledged that he was not one of the roughly half-dozen agents present during Clinton's questioning.