According to people familiar with the Russia dossier, Hillary Clinton‘s campaign, as well as the Democratic National Committee, helped to fund the research that led to the dossier tying Donald Trump to Russia.

Marc E. Elias, a lawyer representing the Clinton campaign and the DNC, reportedly retained the firm Fusion GPS in order to conduct research on Trump, and the firm was the one to hire Christopher Steele, a former British intelligence officer who ultimately authored the infamous dossier.

The campaign retained the firm in April 2016, but Fusion GPS had been researching Trump before that, during the Republican primary, though it is not clear which of the Republican candidates was the one to retain the firm at that time. After the unknown Republican stopped funding the research, Elias, acting on behalf of the DNC and the campaign, agreed to step in because of concerns that not enough was known about Trump and his business ties.

It is not yet clear who in the campaign was aware of the information or Fusion GPS’s role in the dossier. Brian Fallon, a former spokesman for the Clinton campaign, said that he was not aware of the matter during the campaign.

“The first I learned of Christopher Steele or saw any dossier was after the election,” Fallon said. “But if I had gotten handed it last fall, I would have had no problem passing it along and urging reporters to look into it. Opposition research happens on every campaign, and here you had probably the most shadowy guy ever running for president, and the FBI certainly has seen fit to look into it. I probably would have volunteered to go to Europe myself to try and verify if it would have helped get more of this out there before the election.”