FBI director James Comey has disputed Hillary Clinton's characterization of his agency's investigation of her private emails, and said this week they are conducting much more than a simple "security review."

However, the FBI chief's remarks have gone unreported this week by the three major networks.

Comey confirmed Wednesday that the FBI is seriously investigating whether Clinton and her team sent or received classified information over a private, unauthorized email server when she worked at the State Department.

The Democratic front-runner has for months downplayed the situation by referring to it as a "security review" or a "security inquiry." She shrugged off the investigation as recently as this weekend.

Comey, however, said it's an investigation.

"I don't know what [she] means," he said. "We're conducting an investigation. That's the bureau's business. That's what we do."

"I'm not familiar with the term 'security inquiry,'" he added.

The New York Times also reported this week that what, "[b]egan as a security referral … [quickly] became an investigation into whether anyone had committed a crime in handling classified information."

No one involved in the investigation has called it a "security referral" since July of last year, the Times' report added, citing sources familiar with the situation.

Though Fox News, Politico and the Times carried Comey's comments, ABC, CBS and NBC News didn't find them worth mentioning Wednesday evening.

"The story should've been covered on the evening news broadcasts," the Media Research Center noted. Instead, the report added, "it was ignored."