Former Trump campaign advisor George Papadopolous may hold the key to some of the most important questions lawmakers have been asking in recent months about the FBI’s handling of the Russia probe into the Trump campaign: Did the FBI withhold exculpatory evidence from America’s most secret court? And if so, what was it?

And on Thursday the former Trump campaign volunteer said he would testify before lawmakers that the bureau did exactly just that.

“Obviously George Papadopoulos was the reason why this whole Russia investigation was opened,” said Rep. Mark Meadows on Thursday to reporters as he made his way into the closed-door hearing. “Hopefully we’ll learn today what was said and what was not said. I think what will find is that this was not colluding with Russia.”

Papadopoulos pled guilty to Robert Mueller’s Special Counsel in September for one count of lying to the FBI and was sentenced to 14 days in prison. In an interview with SaraACarter.com and John Solomon with The Hill earlier this week, Papadopoulos said that he made it perfectly clear to an undercover bureau operative and British based professor Stefan Halper, that there was no collusion between the Trump campaign and Russia.

George Papadopoulos, the supposed key informant, told the FBI there was no collusion BEFORE the FISA warrant–and the FBI omitted that exculpatory information from the application anyway With all we've learned about FISA abuses, this is deeply troubling https://t.co/tftUHDDOU1 — Mark Meadows (@MarkMeadows) October 24, 2018

Halper, who Papadopoulos suspected in the late summer of 2016 to be recording his conversations, had questioned him extensively in private conversations as to whether or not the Trump campaign had been in communication with Russia. He also questioned whether there was any coordination between Russia and the campaign to obtain Hillary Clinton emails that had been hacked from her server.

“I think I told him something along the lines of I have no idea what the hell you are talking about. What you are talking about is treason. And I have nothing to with that, so stop bothering me about it,” said Papadopoulos, who noted that Halper was asking if the Trump campaign was involved in obtaining or seeking the Hillary Clinton emails WikiLeaks obtained. He said Halper made suggestions that the Trump campaign was involved in the hacking and somehow colluding with Russia on the matter–a claim that Papadopolous found ridiculous and emphatically said was false.

The exchange between Halper and Papadopolous is important because it was this information that was obtained by the FBI that was purposefully kept from the Foreign Intelligence Surveillance Court (FISC) when the FBI and DOJ sought a warrant to gather all the communications and spy on another former Trump campaign advisor, Carter Page.

This is the exculpatory information that the government has fought so hard to keep from the public, say sources with direct knowledge of the investigation. It is also one of the reasons why Republican lawmakers have been battling behind closed doors with the Department of Justice and FBI, both of which have fought vigorously to keep the documents requested by investigators from the public and lawmakers.

The conversation between Halper and then-campaign advisor Papadopolous happened only several weeks after the FBI opened its “Crossfire Hurricane” probe into the Trump campaign on July 31, 2016.

The FBI was well aware that Papadopoulos didn’t believe there was any collusion and knew nothing of collusion from his conversation with Halper

“The FBI was well aware that Papadopoulos didn’t believe there was any collusion and knew nothing of collusion from his conversation with Halper,” said a source with direct knowledge of the investigation. The FBI knew this because the bureau was in possession of the information regarding the conversations between Halper and Papadopoulos but never turned them over to the courts, according to sources with knowledge of the bureau’s investigation.

“He was there to probe me on the behest of somebody else…(Halper) said something along the lines of ‘Oh, it’s great that Russia is helping you and your campaign, right George?’” Papadopoulos said.

Earlier this year, The Washington Post exposed that the confidential bureau informant was Halper. Halper had been reporting back to the bureau on his conversations with Papadopoulos. However, Papadopoulos also suspected Halper of recording him throughout their conversations. Halper offered him $3,000 to assist in a research paper he was writing in order to lure him to London, Papadopolous said. At the time, Halper was also getting hundreds of thousands of dollars from the Pentagon for apparent research, as exposed by whistleblower Adam Lovinger and reported earlier by SaraACarter.com.

In September 2016, Halper reaches out to Papadopoulos with an email, “‘saying I know you’re a known expert on Israeli energy.’ I looked him up and he looked Kosher like I can trust him.”

“But when I get to London things start getting weird right away,” Papadopoulos said.

Papadopoulos wasn’t the only person Halper tried to contact in the Trump campaign. He had contacted Page and former senior Trump campaign advisor, Sam Clovis.

Papadopoulos described his contact with Halper as odd from the beginning. He said he met with a female guide recommended by Halper. When he met her she was scantily dressed and “trying to seduce me and was trying to hint that I want to sleep with you but you have to give some information first.” He declined any advances by the woman and told his wife Simona about the incident, as she confirmed.

Papadopoulos and his wife Simona told SaraACarter.com that there were also other strange meetings with various officials, both U.S. and foreign officials, during his time in London and after he agreed to join the Trump campaign in March 2016.

Some of those of those contacts were initiated by outside players in April, 2016 and continued until October, 2016. Two employees with the U.S. Defense Intelligence Agency, an Australian intelligence agent, an Israeli diplomat, Australian diplomat, and British officials all wanted to connect with Papadopoulos while he was in London, he said.

“They were wining and dining me as if I were Marilyn Monroe,” said Papadopoulos.

He noted that the officials would squeeze in questions regarding his contacts in Athens during dinner and lunch meetings. They would want to know what he was researching and that they would say they were interested in his “contacts in Athens.” At the time, Papadopoulos was serving as a foreign policy adviser to the Trump campaign.

The two defense officials who made contact with him wanted to “find out why Trump was willing to work with Russia. They were trying to act as if they were pro-working with Russia,” said Papadopoulos.

Around the same time, a London professor named Joseph Mifsud, who has been in hiding since his name surfaced in the news, had already told Papadopoulos that the Russians had thousands of emails from Clinton that could expose her wrongdoing. Mifsud also introduces Papadopoulos to a Russian woman, who Mifsud claims later to be a niece of Putin. But Papadopoulos said he didn’t buy that claim either, saying she was an “obscure young girl…who barely spoke English to all of the sudden writing in fluent English in emails to me.”

Papadopoulos said that he didn’t believe he was speaking to the same woman he met through Mifsud.

“I’ve never met a Russian official in my life,” said Papadopoulos, who added that Mifsud’s claims about Clinton’s emails were interesting, but that rumors had already been in the media for months before.

However, Papadopolous contends that he never followed up on what Mifsud was saying about Clinton and Mifsud’s promises to introduce him to senior Russian officials never came to fruition. In fact, he didn’t trust Mifsud, he said.

Shortly after he met with Misfud, another character entered the picture – an Israeli diplomat in London who opposed Trump reached out to him April, 2016. The Israeli official also questioned him about Russia, as well as Trump’s policies on Iran. That official then set up Papadopolous with a woman, the Israeli diplomats girlfriend, who worked for Australian Intelligence. She was very hostile to Trump, he said.

She asked Papadopoulos why he was working for Trump, suggesting a better move would have been to work with Sen. Ted Cruz, R-Texas, Papadopoulos recalls. The girlfriend introduced Papadopoulos to Alexander Downer, who was the Ambassador to Australia at the time. Downer was apparently upset with an interview Papadopoulos gave to the British papers criticizing British Prime Minister David Cameron and asking Cameron “to apologize” to Trump for his comments about the then presidential candidate.

It was at a May 10, 2016 meeting with Downer that Downer claims Papadopoulos told him that the Russians had information on Clinton.

Papadopoulos said he doesn’t remember telling Downer about the email claim, but does remember saying something to the Greek foreign minister who was discussing a meeting he was planning to have with Russian President Vladimir Putin.

“Where you are sitting now Putin will be sitting there tomorrow,’ the Greek foreign minister told him.

“I just had this nervous reaction and said ‘Oh, hey, I heard this thing about emails,’” said Papadopoulos.”It was nothing else,”

As for Halper, Papadopoulos said he remembers a meeting in a London club where Halper kept putting his phone closer to his face.

“He puts his phone out in front of him and right away I saw what he was doing. This guy is obviously recording me,” said Papadopoulos, who noted that he never relayed the information on the claims of the Russian emails to campaign officials because he didn’t think there was much to the claim.

But Halper he said insisted that night at the London Club and questioned him about the Clinton emails. At that point he told Halper, “That would be treason, I don’t know what you are talking about and I have nothing to do with Russia.”

It is this same testimony that Papadopoulos delivered to lawmakers Thursday, according to what Papadopoulos said he would be discussing.