FBI agent Peter Strzok would not reveal Thursday while testifying in front of House lawmakers how he had access to three copies from different sources of the infamous "Trump dossier."

During the multi-hour hearing, Rep. Jim Jordan, R-Ohio, read an email sent by Strzok to other members of the FBI, that pointed out the dossier published by BuzzFeed News was identical to the documents that Sen. John McCain, R-Ariz., had passed along to the FBI. In the email, Strzok noted that the dossier “has differences from what was given to us by Corn and Simpson.”

[Related: Republicans threaten Peter Strzok with contempt for refusing to answer first question in tense hearing]

Jordan pressed Strzok on the identities of Corn and Simpson. Strzok declined to the answer the question, though Jordan specifically asked whether the email referred to journalist David Corn and Fusion GPS founder Glenn Simpson. Strzok said he had not communicated with either of the men.

When asked if he ever communicated with Bruce Ohr, a Justice Department official who had been in contact with former British intelligence agent Christopher Steele, who compiled the dossier for Fusion GPS, or his wife Nellie Ohr, who was employed by Fusion GPS, Strzok said he had spoken with Bruce Ohr anywhere from three to five times from late 2016 to early 2017.

“We talked about investigative matters that Mr. Ohr was involved in,” Strzok said.

Simpson previously testified to the Senate Judiciary Committee in August 2017 that no one from Fusion GPS had ever spoken with the FBI.

“Here's what I'm having trouble understanding,” Jordan said. “If Glenn Simpson says no one ever spoke with the FBI, how is it that you got a copy of the dossier from Simpson?”

“Sir, I can tell you I never had contact with Fusion, with Mr. Simpson, with Mr. Corn,” Strzok said.