The investigation, being conducted by FTI Consulting, is running in parallel to special counsel Robert Mueller’s probe into possible collusion between the Trump campaign and Russia in Kremlin-directed efforts to interfere with the 2016 presidential election. With the special counsel probe under wraps, the BuzzFeed court case could represent the first public airing of an investigation into the veracity of some of the dossier’s claims.

FTI is a Washington-based business advisory firm that specializes in areas ranging from corporate litigation to forensic accounting, and it is a frequent post-government landing pad for FBI officials.

The ramifications of FTI’s dossier investigation could be game-changing for Mueller’s probe, because it “would establish outside veracity of dossier allegations,” a source familiar with the work told Foreign Policy. Yet news of FTI’s involvement, including the critical role of a former top FBI official, would also be controversial because the dossier itself is “a political football,” the source said.