Former White House chief strategist Steve Bannon said in court on Friday that he and the Trump campaign viewed Roger Stone, a longtime Donald Trump associate, as an access point to WikiLeaks, the organization that leaked stolen emails that were damaging to Hillary Clinton’s campaign.

Bannon said that during the Trump 2016 campaign, Stone “implied” that WikiLeaks had materials that would help Donald Trump and possibly hurt Hillary Clinton’s chance at the presidency.

With his 40-minute testimony, Bannon became the most high-profile witness to testify at Stone’s trial. He made clear in his testimony and to reporters as he left the federal courthouse in Washington, DC, that he was only appearing because he had been compelled to by a subpoena. Bannon’s testimony marks the start in the case of federal prosecutors beginning to tie Trump and his campaign to trying to use WikiLeaks to their advantage.