Fusion GPS co-founder Glenn Simpson appeared before the House Intelligence Committee in closed session for seven hours on Tuesday as part of its investigation into Russian interference in the 2016 campaign and possible collusion between President Trump and the Kremlin.

The committee will determine if the transcript will be released, according to Simpson’s lawyer.

“The transcript is the property of the committee, and it is up to the committee whether it will release it,” Simpson’s lawyer, Joshua Levy, said in a statement Tuesday.

Fusion GPS, a Washington opposition research firm, was hired by lawyer Mark Elias, who represented Hillary Clinton's campaign and the Democratic National Committee, to oversee the research, according to a Washington Post report. Fusion GPS then hired former British intelligence officer Christopher Steele, who authored the so-called "Trump dossier," which contained scandalous claims about President Trump's ties to Russia.

Elias and Perkins Coie, his law firm, hired Fusion GPS in April 2016. Fusion GPS had already been conducting research on Trump during the Republican primaries for the conservative Washington Free Beacon, the Washington Examiner first reported.

“The White House and its political allies have attempted at every turn to smear Fusion GPS because of its connection to the Steele dossier, whose findings are the subject of multiple investigations into the Trump campaign’s collusion with the Russians,” Levy said in the statement.

The Clinton campaign and the DNC financed Fusion GPS's research up until just days before the Nov. 8 election.

Some aspects of the dossier — like communications between foreign nationals noted in the dossier — have been confirmed by officials; however, the majority of the scandalous allegations included in the document have not been verified.

The dossier came to light publicly after it was published in full by BuzzFeed in January.