The messages between Peter Strzok and Lisa Page are of particular interest to Republicans who believe there is an anti-Donald Trump bias at the FBI. Strzok, who was romantically involved with Page, was a member of the FBI team investigating Hillary Clinton's email server and, later, a member of Robert Mueller's special counsel operation looking into Russia's attempt to interfere in the 2016 election.
In a letter to lawmakers on Thursday, Justice Department Inspector General Michael Horowitz wrote that this week his office was able to recover texts sent between Strzok and Page over a five-month span from December 2016 to May 2017.
"The OIG has been investigating this matter and, this week, succeeded in using forensic tools to recover text messages from FBI devices, including text messages between Mr. Strzok and Ms. Page that were sent or received between December 14, 2016, and May 17, 2017," Horowitz wrote in the letter, which was provided to CNN by the office of Senate Homeland Security Committee Chairman Ron Johnson, R-Wisconsin.
The gap in the exchange between the top FBI officials was revealed to lawmakers by the Justice Department as it produced a second batch of the pair's text messages to six congressional committees
over the weekend. The texts themselves were first discovered as part of an internal investigation by the inspector general into the FBI's handling of the Clinton email investigation.
Trump has called the matter "one of the biggest stories in a long time," and Attorney General Jeff Sessions has promised to "leave no stone unturned" in an investigation to determine how the messages, sent on bureau-issued phones, were not collected by the FBI's retention software.
It is not clear how many texts the inspector general's office has recovered from the missing period. Sessions has said that outside of the five-month span, more than 50,000 texts that were exchanged between the two officials have been collected and scrutinized by the office.
In the letter, Horowitz wrote that his office would provide copies of the text messages recovered from the device to the Justice Department and that he would have "no objection to the department providing its own records to your committees in response to a congressional oversight request should department leadership deem it appropriate to do so, and consistent with applicable law and department policy."
The inspector general's office is continuing its effort to recover any additional text messages exchanged by the pair, Horowitz wrote.
In a cover letter accompanying the Friday delivery of 384 new pages of the officials' texts, Assistant Attorney General Stephen Boyd explained that technical issues with the FBI's retention software prevented the bureau from capturing messages sent between the two employees on their agency-issued phones during that period.
"The FBI has informed us that many FBI-provided Samsung 5 mobile devices did not capture or store text messages due to misconfiguration issues related to rollouts, provisioning, and software upgrades that conflicted with the FBI's collection capabilities," Boyd said.
Sources told CNN on Wednesday that about one in 10 FBI phones were affected by the glitch -- totaling in the thousands.
Fodder for conspiracy theorists
The missing texts had become fodder for conspiracy theories on Capitol Hill and cable news. May 17, 2017, the final day that the pair's messages were not captured by the FBI's system, was also the day that Deputy Attorney General Rod Rosenstein first appointed Mueller as special counsel.
Among the volumes of messages sent between the two officials were insults flung at politicians on both sides of the aisle as well as discussions that Republicans have held up as examples of bias and corruption at the top ranks of the FBI.
One of the text messages that has been previously surfaced includes a reference to a "secret society." But the message does not reveal
an obvious intention behind the exchange, raising the possibility that it may have been an off-hand remark or joke.
Strzok was reassigned to the FBI's human resources office after the discovery of the messages. Page was also briefly on Mueller's team before returning to the FBI, but she completed her detail before the special counsel's office was made aware of the texts.