Hillary Clinton may soon face a second FBI investigation related to her private email use thanks to a criminal referral from congressional Republicans based on misstatements the former secretary of state made under oath.

Rep. Jason Chaffetz, chairman of the House Oversight Committee, vowed to make such a referral to the FBI Thursday after its director, James Comey, said Clinton's sworn testimony last year before the House Select Committee on Benghazi was not considered as evidence by investigators because his agency did not receive a referral.

Rep. Trey Gowdy, chairman of the Benghazi committee, and Rep. Bob Goodlatte, chairman of the House Judiciary Committee, are set to lead the filing of a joint referral alongside Chaffetz, a committee source told the Washington Examiner. The referral will likely take the form of a letter Friday highlighting discrepancies between Comey's words and Clinton's.

During the Benghazi committee hearing in October, Clinton repeated several talking points about her emails that were exposed as falsehoods by Comey earlier this week and explored in greater detail at the oversight hearing Thursday.

"We have no basis to conclude that she lied to the FBI," Comey said when asked about the veracity of Clinton's statements.

But the FBI director stopped short of saying Clinton had not lied to the public.

When asked whether the FBI had looked at inconsistencies in Clinton's congressional testimony, Comey said the agency hadn't factored that hearing into its final decision because it hadn't received a referral from Congress to do so.

"You'll get one," Chaffetz replied.

Clinton was not placed under oath for her interview with the FBI Saturday, which was the last step in a nearly year-long investigation.

The "five or six" agents who questioned Clinton did not transcribe or record their session.

Comey could not answer the majority of questions about what Clinton told investigators in her interview, but he concluded he did not have evidence that she lied to the FBI. Doing so would be a crime, he said.

In her Benghazi committee testimony, Clinton made several assertions about her email use that Comey contradicted directly Thursday.

For example, she told Rep. Jim Jordan in an exchange during the Benghazi hearing that her attorneys had carefully screened all of her emails to determine which were work-related:

JORDAN: Will you provide this committee — or can you answer today, what were the search terms?

CLINTON: The search terms were everything you could imagine that might be related to anything, but they also went through every single e-mail.

But during the oversight hearing Thursday, Comey said thousands of work-related emails were not included in the batch Clinton provided the State Department because her attorneys' screening process consisted only of keyword searches.

"On October 22nd, former Secretary of State Hillary Clinton testified under oath before Congress that 'there was nothing marked classified' on any emails she sent or received," Jordan said after the hearing. "On July 7th, FBI Director James Comey testified that her statement to Congress was not true."

The criminal referral could delay Clinton's ability to move on from the controversy over her emails by prolonging the focus on her misconduct.

Comey noted during the oversight hearing that perjury is a crime potentially punishable by prison time.

Many of the questions asked of Comey Thursday focused on whether Clinton had misrepresented her private email use to the public by repeatedly arguing she had not handled anything marked classified.

Clinton has frequently touted her commitment to transparency when defending her record-keeping practices, pointing to her production of roughly 30,000 printed emails to the State Department in 2014.

However, Comey suggested at least some of the thousands of work-related and even classified emails Clinton withheld had been deleted using means that rendered the records irretrievable.

The FBI director declined to comment on whether the FBI continues to investigate the Clinton Foundation for allegations of public corruption, as reports made public earlier this year suggested.

His refusal to rule out an ongoing Clinton Foundation corruption probe is sure to stoke speculation that the well-connected philanthropic group could still be the subject of a probe.