The Justice Department is intent on reviewing transcripts of recordings that at least one government informant made of conversations with former Trump campaign associate George Papadopoulos.

Little is known about these classified transcripts, including who is the source, other than the growing hype about them in conservative circles. Former Rep. Trey Gowdy called them a "game changer" in a Fox News interview in May.

But progress is being made to peel back the mystery, according to a Fox News report, as Attorney General William Barr and U.S. Attorney John Durham's investigation into the origins of the Russia investigation and possible misconduct by DOJ and FBI officials ramps up.

A key element to their disclosure may be President Trump granting Barr “full and complete authority to declassify information” in the Justice Department inquiry.

Trump expressed confidence in Barr during a Fox News interview Thursday evening, reiterating Barr's power to uncover and release information related to the inquiry. "Anything he needs, he's got it,” Trump said.

Barr tasked Durham, who hails from Connecticut, with leading the inquiry sometime in the spring.

Investigators looking at why certain "exculpatory" material from these transcripts was not presented in subsequent applications for surveillance warrants against another Trump campaign aide, Carter Page.

“I think it’s the smoking gun,” one source said.

Without Trump's declassification order, one source said Director of National Intelligence Dan Coats would not have allowed anyone to have access to these mysterious records. But another source stressed that Coats as well as FBI Director Christopher Wray and CIA Director Gina Haspel are cooperating with DOJ's investigation.

Papadopoulos was swept up in Robert Mueller’s special counsel investigation, under suspicion of trying to make inroads with the Russians. His interactions with the mysterious Maltese academic Joseph Mifsud allegedly led to the FBI opening a counterintelligence inquiry into the Trump campaign in July 2016, which predated Mueller's appointment. Papadopoulos pleaded guilty in October 2017 to making false statements to the FBI about his contacts with Mifsud and served just 12 days in federal prison late last year. He is now on supervised release.

Mueller's report said that during a 2016 meeting in London, Mifsud informed Papadopoulos that he learned that the Russians had “dirt” on Hillary Clinton, Trump's presidential rival, in the form of "thousands of emails." Papadopoulos later repeated this claim to Australian diplomat Alexander Downer, who informed the U.S. government and the FBI says this prompted the original counterintelligence investigation into Trump's campaign. Mifsud has denied that he told Papadopoulos the Russians had Clinton's emails.

Papadopoulos also said he told the Greek foreign minister that the Russians had damaging information about Clinton.

During his testimony before the House Judiciary and Intelligence committees on Wednesday, Mueller repeatedly shot down GOP attempts to get him to discuss the early stages of the counterintelligence investigation that preceded his May 2017 appointment as special counsel, including why Mifsud was never charged for lying.

A report published by the Hill on the eve of Mueller's testimony this week said Durham's investigators have reached out to Mifsud's attorney to set up an interview with Mifsud, who has laid low for the past couple years. Democratic National Committee lawyers said last year Mifsud may even be dead.

The transcripts that are now a focus of Durham's inquiry may come from conversations Papadopoulos had with Stefan Halper, an American professor at Cambridge University who is believed to be an FBI informant, and a woman who posed as his assistant and called herself Azra Turk.

During one of Papadopoulos' meetings with Halper in September 2016, the woman identified as Turk asked him point blank if Trump's campaign was working with the Russians to get hacked emails. Papadopoulos discussed this woman in his book, Deep State Target. He doubted she was being forthcoming about her identity.

The FBI has cited Papadopoulos' telling Downer about the Russians having dirt on Clinton as the reason the bureau officially began the Trump-Russia investigation, known as Crossfire Hurricane, on July 31, 2016. But a source said another element of the DOJ investigation is to determine the actual “start date” of the investigation, as Republican lawmakers such as Devin Nunes say it may have started earlier.