FIRST ON FOX: A group of House Republicans is going directly to Defense Secretary Lloyd Austin for more information on the decision-making that led to senior officials in the White House and Pentagon reportedly being in the dark for days about Austin’s recent hospitalization.

Rep. Claudia Tenney, R-N.Y., led a group of two dozen GOP lawmakers in writing a letter to Austin with questions about who was part of the decision to delay disclosure, how Austin would respond ‘if one of your combatant commanders was unable to discharge the duties of their office for three or four days and you were not informed’ and who was in the loop about his situation from the beginning, among other details.

‘First and foremost, we wish you a speedy recovery and are sorry to hear about your recent cancer diagnosis. We are glad to hear that you are now recuperating and have been moved out of the ICU,’ reads the letter exclusively obtained by Fox News Digital.

‘However, we are gravely concerned about the lack of transparency from the Department of Defense (DOD) regarding your recent hospitalization, which included a four-day stint in the intensive care unit,’ it continues.

‘According to reports, congressional leadership, the Deputy Defense Secretary, the President, the National Security Advisor, and other members of the National Security Council were not informed about your hospitalization until three days after your hospital admission. Given your critical role in protecting our nation as Secretary of Defense, it is deeply concerning that you kept your extended hospital stay a secret from the President and other senior national security officials.’

It comes as pressure mounts on the Pentagon over Austin’s hospitalization and cancer diagnosis, and how they were disclosed. The Defense Department’s inspector general said Thursday they’re looking into the matter.

The Pentagon publicly revealed on Jan. 5 that Austin had been in the hospital since Jan. 1 due to complications from elective surgery. But a Politico report later revealed that not only was the media kept in the dark, the highest levels of the White House and top officials in the Pentagon itself were not aware until Jan. 4 that Austin was in the hospital.

The non-disclosure prompted a flurry of bipartisan concern, with top Democrats and Republicans on the House and Senate Armed Services committees calling for more transparency about the incident.

Austin’s doctors announced on Tuesday that he had been treated for prostate cancer. On the same day, National Security Council spokesman John Kirby said, ‘Nobody at the White House knew that Secretary Austin had prostate cancer until this morning.’

Meanwhile, Armed Services Committee Chair Mike Rogers, R-Ala., led a letter to Austin on Wednesday, similarly pushing him to give Congress more answers.

‘With conflicts around the world, it is preposterous that you and others in the Department allowed this to occur. This level of confusion surrounding not only your whereabouts, but your capacity to lead the Department has shaken what little confidence existed in any previous commitment to transparency,’ the letter reads.