Retired Lt. Gen. Michael Flynn has terminated his attorneys and replaced them with a new legal team as the former top Trump official awaits sentencing after pleading guilty in 2017 to making false statements to the FBI regarding his communications with then-Russian Ambassador Sergey Kislyak.

According to a court filing made public Thursday, Flynn has advised his lawyers, Stephen Anthony and Robert Kelner, that he is “terminating Covington & Burling LLP as his counsel.” The filing reads that President Donald Trump’s first national security adviser “has already retained new counsel for this matter.”

The motive behind the dramatic change is presently unclear. Neither Flynn, nor his former lawyers, have issued a statement on the change.

In March, ABC News reported that Flynn had amassed legal fees totaling around $5 million.

He has relied partly on the Michael T. Flynn Legal Defense Fund, established by family and friends of the retired army man, to help pay for his mounting legal bills. Flynn has reportedly opted not to take money from Patriot Legal Expense Fund, set up with Trump campaign funds to help his campaign staff cover their bills related to the Mueller probe. “General Flynn early on made a decision not to accept funds from President Trump, the Trump Organization, or the campaign, and has not accepted any funds from them,” one source told ABC News, adding, “And he does not expect to accept any funds from the new entity.”

The development comes after a federal judge said Tuesday that prosecutors no longer have to publicly file a transcript of the call between Flynn and the Russian ambassador to the United States, reversing course from an order last month.

U.S. District Judge Emmet Sullivan had earlier directed prosecutors to make public details of a December 2016 call in which Flynn, President Donald Trump’s first national security adviser, discussed sanctions with Kislyak.

He also ordered them to produce redacted portions of special counsel Robert Mueller’s report that relate to Flynn, as well as a transcript of a phone message a lawyer for President Trump left for Flynn’s attorney after Flynn had decided to start cooperating with prosecutors.

Last Friday, on the deadline set by the judge, prosecutors publicly filed the transcript of the call between the lawyers and said all of the information in the report that Flynn had provided had been unredacted. However, they declined to produce a transcript of Flynn’s call with Kislyak, saying they were not relying on that conversation to establish his guilt or to determine his sentence.

The Associated Press contributed to this report.