WDRB first broke the story, which has caused Republican critics to question the length of the investigation, when the governor knew, and whether there are gaps in the system that allowed the licenses to be improperly issued.
Wednesday, Beshear said during his Team Kentucky update that the Kentucky Transportation Cabinet identified irregularities during a regular review and revoked nearly 2,000 credentials.
"To our knowledge, all employees involved have been hired through a temp agency and have been terminated. KYTC immediately contacted law enforcement, who are engaged in a criminal investigation, and it includes multiple offices that are both state and federal," he told reporters.
Beshear said he would have to review when he became aware of the irregularities and did not confirm whether the credentials were obtained by undocumented immigrants, saying the investigation is ongoing.
As for a whistleblower suit that alleges a cabinet employee was fired after reporting the incidents, Beshear offered few details.
"I haven't read that complaint. What I do know is that there are at least some statements in that complaint that are not factual, and that don't follow how the original investigation went," he said.
The governor said the state and his office are committed to holding anyone involved accountable.
Meanwhile, Republican lawmakers are launching an investigation of their own and seeking a review by the attorney general.