(The Hill) – The Department of Defense (DOD) failed to retain text messages from a number of its top officials relating to the Jan. 6, 2021, Capitol riot because it wiped their phones during the transition, a watchdog group that sued for the records disclosed Tuesday.

American Oversight filed a public records request for the communications of former acting Defense Secretary Chris Miller and former Army Secretary Ryan McCarthy in the days after the attack on the Capitol.

But they were informed during litigation that the records were not preserved.

“DOD and Army conveyed to Plaintiff that when an employee separates from DOD or Army he or she turns in the government-issued phone, and the phone is wiped. For those custodians no longer with the agency, the text messages were not preserved and therefore could not be searched,” the agencies wrote in a March court filing.

The disclosure follows news that numerous officials at the Department of Homeland Security (DHS) also had their messages erased during the transition, including former acting Secretary Chad Wolf and his deputy, Ken Cuccinelli. Both had their phones reset following the inauguration, losing any texts from Jan. 6 in the process.

The inspector general at DHS also notified Congress last month that text messages from Jan. 5 and Jan. 6 were “erased” as part of a device replacement program.

The Secret Service contends any text messages that might be missing were lost through a software transition.

The effort to obtain Pentagon texts could have shed light on why the National Guard faced delays in getting approval to go to the Capitol as it was under siege.

The suit sought the military leaders’ communications with former President Donald Trump, former Vice President Mike Pence and Trump’s chief of staff Mark Meadows. The request also asked for communications from Kash Patel, Miller’s chief of staff; Paul Ney, the Defense Department general counsel; and James E. McPherson, the Army’s general counsel.

Patel was also subpoenaed by the House committee investigating the Jan. 6 attack on the Capitol.

American Oversight sent a letter to Attorney General Merrick Garland to investigate, noting that each official’s phone appears to have been wiped after their records request was filed.

“DOD has apparently deleted messages from top DOD and Army officials responsive to pending FOIA requests that could have shed light on the actions of top Trump administration officials on the day of the failed insurrection,” Heather Sawyer, the group’s executive director, wrote in the letter, referring to the Freedom of Information Act.

“American Oversight accordingly urges you to investigate DOD’s actions in allowing the destruction of records potentially relevant to this significant matter of national attention and historical importance.”

Both DOD and the Justice Department declined to comment.

It’s the second time in less than a week that Garland has been called upon to intervene in a Jan. 6-related matter.

Senate Judiciary Committee Chairman Dick Durbin (D-Ill.) penned a letter to the attorney general last week asking him to review what he called “the destruction of evidence” at DHS. Durbin also asked Garland to “step in and get to the bottom of what happened to these text messages and hold accountable those who are responsible.”