Republican politicians have formally asked the US Justice Department to investigate Hillary Clinton and determine whether she lied to Congress, in a fresh challenge certain to shadow the Democratic presidential candidate.
Meanwhile, the director of national intelligence rejected a request from House of Representatives speaker Paul Ryan to deny Mrs Clinton access to secret intelligence briefings during the campaign.
The Republican Party was furious that the FBI decided against pressing charges against Mrs Clinton over her handling of classified information when she relied on a private email server for government business during her tenure as Secretary of State.
Republicans have vowed to press ahead just a few months before the November election.
Congressmen Jason Chaffetz, chairman of the oversight panel, and Bob Goodlatte, head of the judiciary committee, said in a letter that "evidence collected by the FBI during its investigation of Secretary Clinton's use of a personal email system appears to directly contradict several aspects of her sworn testimony".
"In light of those contradictions, the department should investigate and determine whether to prosecute Secretary Clinton for violating statutes that prohibit perjury and false statements to Congress, or any other relevant statutes," the congressmen wrote.
In evidence to the House of Representatives' Benghazi panel last October, Mrs Clinton said she never sent or received emails marked as classified when she served as secretary of state.
She has also said she only used one mobile device for emails and turned over all her work-related emails to the State Department.
FBI director James Comey said she had multiple devices and investigators found thousands of work-related emails that had not been turned over.
He told Congress last week that three of her emails carried classified markings.
The Congressmen's letter was addressed to the US Attorney for the District of Columbia, Channing Phillips.
Last week, the Justice Department closed the investigation of Mrs Clinton after the year-long FBI probe.
Mr Comey said there were no grounds to prosecute Mrs Clinton but she and her aides had been "extremely careless" in their handling of classified information.
After Mr Comey's remarks, Mr Ryan sent a letter to director of national intelligence James Clapper, suggesting that Mrs Clinton be denied access to such information during her presidential run.
Mr Clapper rejected that request in a letter sent to Mr Ryan on Monday, saying: "I do not intend to withhold briefings from any officially nominated, eligible candidate."
He pointed out that presidential and vice-presidential candidates had received such briefings since President Harry Truman initiated them in 1952 and they were "provided on an even-handed, non-partisan basis".
Mrs Clinton said last week that she exchanged emails with about 300 people, mostly at the State Department, who were experienced with handling classified information.
"They did not believe that (material in the emails) was classified, and I did not have a basis for second-guessing their conclusion," she told CNN. "I have no reason to believe they were careless."
Referrals from Congress do not automatically result in full-fledged investigations, but they have spurred some notable criminal probes and indictments.
Former baseball pitcher Roger Clemens was indicted in 2010 on charges that he lied to Congress, though he was later acquitted, and the Justice Department investigated and later cleared former Internal Revenue Service official Lois Lerner following a referral from politicians.
Mr Chaffetz also sent a letter to Mr Comey seeking the investigative file from the probe.
Elijah Cummings of Maryland, the top Democrat on the oversight committee, said in response to the criminal referral that "Republicans are so frustrated with the FBI's unanimous decision that they are now completely unloading on Secretary Clinton with everything they've got - right before the presidential conventions".
The Republican convention begins on July 18. The Democratic convention is a week later.