(Reuters) - The U.S. District Court for the District of Columbia judge presiding over the criminal case for President Donald Trump’s former National Security Adviser Michael Flynn has been recused from handling the case, a court spokeswoman said on Thursday.

FILE PHOTO: Former U.S. National Security Adviser Michael Flynn arrives for a plea hearing at U.S. District Court, where he’s expected to plead guilty to lying to the FBI about his contacts with Russia's ambassador to the United States, in Washington, U.S., December 1, 2017. REUTERS/Jonathan Ernst

According to a court filing, U.S. District Court Judge Rudolph Contreras, who presided over a Dec. 1 hearing where Flynn pleaded guilty to lying to the Federal Bureau of Investigation about his contacts with Russia, will no longer handle the case.

Court spokeswoman Lisa Klem did not say why Contreras was recused, and added that the case was randomly reassigned.

Reuters could not immediately learn the reason for the recusal, or reach Contreras.

An attorney for Flynn declined to comment.

Now, Flynn’s sentencing will be overseen by U.S. District Court Judge Emmet Sullivan. Sullivan was appointed by former Democratic President Bill Clinton.

Flynn was the first member of Trump’s administration to plead guilty to a crime uncovered by Special Counsel Robert Mueller’s wide-ranging probe into Russian attempts to influence the 2016 U.S. presidential election and potential collusion by Trump aides. Russia has denied meddling in the election and Trump has dismissed any suggestion of collusion.

Flynn has agreed to cooperate with Mueller’s ongoing investigation.

A sentencing date has not yet been set, but the parties are due to return to court on February 1 for a status report hearing.

Contreras was appointed to the bench in 2012 by former Democratic President Barack Obama.

He was also appointed to the Foreign Intelligence Surveillance Court in May 2016 for a term lasting through 2023.

That court issues warrants that allow Justice Department officials to wiretap individuals, a process that has been thrown into the spotlight amid the investigation into alleged Russian interference in the U.S. election.

The most recent controversy related to FISA warrants involves Peter Strzok, a senior FBI agent who was removed from the Russia investigation for exchanging text messages with a colleague that expressed anti-Trump views.

At a hearing on Thursday at the House Judiciary Committee, Republican lawmaker Jim Jordan pressed FBI Director Christopher Wray on whether a former British spy’s dossier of allegations of Russian financial and personal links to Trump’s campaign and associates was used by Strzok to obtain a FISA warrant to surveil Trump’s transition team.

Judge Sullivan previously served on the Superior Court of the District of Columbia and the District of Columbia Court of Appeals under appointments by Republican Presidents Ronald Reagan and George H.W. Bush, respectively.