Story highlights Mary McCord has spent decades as a career prosecutor

Her replacement has not been announced

(CNN) One of the top officials at the Justice Department overseeing the FBI's probe of potential coordination between the Trump campaign and Russian meddling in the presidential election will leave the department next month.

Mary McCord -- a career prosecutor for over 20 years -- has been serving as acting assistant attorney general at the National Security Division since John Carlin, an Obama appointee, resigned last fall. McCord joined the division as a non-political appointee in 2014 as the principal deputy assistant attorney general from the US Attorney's Office in DC.

Justice Department spokesperson Marc Raimondi confirmed that McCord informed DOJ leadership of her departure on Monday, but per department protocols, she did not reveal in an email to staff what she will do next.

McCord has held one of the more demanding jobs within the department, as the national security division handles counterterrorism and counterespionage prosecutions, as well as Foreign Intelligence Surveillance Act (FISA) warrants.

Last month, FBI Director James Comey publicly confirmed for the first time that his agency has been investigating possible "coordination" between Russia and the Trump campaign, and whether any crimes may have been committed as part of a wider probe into the hacking of Democratic servers and Hillary Clinton's campaign.

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