(CNN) When the FBI started to look into the campaign of President Donald Trump and its ties to Russia in the summer of 2016, the agency took steps to make sure it did not make waves before the election, according to a report by The New York Times.

At the beginning of the investigation, the bureau dispatched two agents to London to interview Australian Ambassador Alexander Downer, who reportedly had proof that one of Trump's advisers knew about Russia's meddling in the 2016 election before it occurred.

The paper reports that the mission, named "Crossfire Hurricane" after a Rolling Stones lyric, was only known to a handful of FBI officials.

The FBI, in an attempt to prevent leaks, kept details about what would later evolve into special counsel Robert Mueller's investigation from Justice Department political appointees. In fact, according to The New York Times, only about five Justice officials knew what the whole case entailed -- a far lower number than the 12 or so who would typically be read in on a case related to national security.

This comes with the one-year anniversary of Mueller's appointment to oversee the federal investigation into Russian interference in the 2016 election, including potential collusion between Trump's campaign associates and Russian officials. The investigation has run parallel to investigations by multiple congressional committees.

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