Justice Department officials are investigating a years-old classified Russian intelligence document leak and whether former F.B.I director James Comey was the person who illegally provided reporters with information, The New York Times reports.

The probe is the second time federal officials have a looked into Comey regarding leaked information. The former FBI head has been frequently labeled a "leaker" by President Trump. What makes this investigation abnormal, though, is that federal prosecutors usually investigate leaks when classified information is reported by the press, not years after the fact, the Times reports.

Sources familiar with the situation told the paper that prosecutors, in particular, are looking into two articles that were written by the Times and The Washington Post in 2017 that mentioned the classified Russian government document.

The document that was mentioned reportedly played a large role in Comey announcing in July 2016 the FBI's decision to not recommend charges for former Secretary of State Hillary Clinton regarding her use of a private email server to conduct government business.

According to the Times's sources, the investigation began in the last couple of months, but why it was initiated and what stage it's at remains unclear.

Comey's counsel and a spokeswoman for the U.S. attorney's office in Washington, D.C., declined the Times's request for comment.