The Defense Department Inspector General is now investigating whether Pete Hegseth attempted to cover up his use of Signal to share sensitive military information.
The Army Times reported on Friday that two people familiar with the investigation by the Pentagon watchdog revealed details to the Associated Press about the matter.
A previous IG investigation was announced last month to more specifically probe the Signal chat itself, which contained secret information about airstrikes on Houthi targets on March 15. Some of the chats included Hegseth's wife and brother, while another included The Atlantic's Jeffrey Goldberg.
The new investigation is likely to interview current and former staff about Hegseth's behavior that day and whether anyone other than him had access to his phone, the two people told the AP.
Hegseth is set to testify to Congress for the first time since the incident next week. The report noted that the questions will likely involve his handling of top-secret information. There may also be questions about resignations from "several senior aides" and Hegseth's attempt to find where leaks were coming from inside his staff.
"Hegseth already has faced questions over the installation of an unsecured internet line in his office that bypassed the Pentagon’s security protocols," the report recalled.
The former DOD inspector general, Robert Storch, was fired by Trump in January.
Trump explained, "I don't know them. But some people thought that some were unfair, or some were not doing their job. It's a very standard thing to do."
The report said that the Defense Department wouldn't comment on the matter.