Newly-revealed interviews show the stunningly comprehensive scope of Mueller's Russia probe
Robert Mueller, the Special Counsel overseeing the investigation into possible collusion between Russians and the Trump campaign in the 2016 election, continues to keep his cards close to his chest as his probe circles the White House AFP/File / SAUL LOEB

While the big fish speared by special counsel Robert Mueller have relentlessly made headlines, his lesser-known potential witnesses may flesh out the story behind the Trump-Russia collusion probe.

The Atlantic's Natasha Bertrand wrote Monday that an associate of a shadowy professor linked to former Trump campaign aide George Papadopoulos revealed in his new book that he'd been interviewed by Mueller's team — and in doing so, showcased how "expansive" the special counsel's probe has become.

In his book titled "The Faking of RUSSIA-GATE: The Papadopoulos Case," German lawyer Stephan Roh — a close associate to Maltese professor Joseph Mifsud, the man who allegedly told Papadopoulos that Russia had "dirt" on Hillary Clinton — wrote that Mueller's team intercepted and interrogated him for "hours" last October in New York.

According to Bertrand's report, two other "obscure players" — Ivan Timofeev, a program director at a Kremlin-funded think tank and Ted Malloch, a British academic tied to Roger Stone — were also interviewed by Mueller's team. Roh and Malloch, who wrote a similar book aiming to "debunk" the Russia investigation titled "The Plot to Destroy Trump: How the Deep State Fabricated the Russia Dossier to Subvert the President," argue another conspiracy is at play — one involving "Western intelligence" planting figures like Papadopoulos to "trick" the Trump campaign into collusion.

Roh's book also claims that Mifsud "has been requested to hide, not to communicate, and not to speak to the press" by the Italian secret services. Though that claim has not been corroborated, the professor has been so far out of the public eye that in February, BuzzFeed News reported that a woman claiming to be Mifsud's fiancée believed him to be missing and hadn't spoken to him in months.