Trump and his allies are accused of of promoting false claims that the election was rigged, pressuring state and federal officials to alter the and assembling fake slates of electors.
Trump, who is the frontrunner for the 2024 Republican presidential nomination, has repeatedly claimed, without evidence, that the 2020 election was stolen from him.
The lawsuit, filed in October 2022, highlighted five instances in which CNN either published stories or aired comments referring to Trump's assertions.
The department said both have worked with Aleksandr Viktorovich Ionov, a Russian the US Justice Department charged last year with conducting a multi-year effort to interfere in US elections
A poll showed an American public unenthused by the prospect of a rematch between Biden and his predecessor and current leading Republican rival, Donald Trump.
The special grand jury does not have the authority to issue indictment and so will need to seek a regular grand jury's approval.