Special counsel Robert Mueller expressed concern in late March about how Attorney General William Barr “publicized” the Mueller Report’s conclusions in the summaries he gave to Congress before releasing the full report.

In a March 27 letter—just three days after Barr sent his report summary to Congress—Mueller said Barr’s own take on the findings “did not fully capture the context, nature, and substance of this office’s work and conclusions,” according to The Washington Post.

“There is now public confusion about critical aspects of the results of our investigation,” Mueller wrote. “This threatens to undermine a central purpose for which the Department appointed the Special Counsel: to assure full public confidence in the outcome of the investigations.”

The letter also requested Barr release the report’s “introductions and executive summaries,” in order to “alleviate the misunderstandings that have arisen” among the public and Congress about the probe.

The letter was reportedly followed by a 15-minute phone call between the two, in which Mueller said he was concerned about the news coverage about the obstruction of justice portion of the investigation. While the special counsel reportedly did not think Barr’s letter to Congress was “inaccurate,” he feared that media coverage of the probe was “creating public misunderstandings” about his office’s work.

In the summaries Barr sent to Congress, he wrote that Mueller and his team “did not draw a conclusion—one way or the other—as to whether the examined conduct constituted obstruction.” Barr then went onto write that the report outlined “no actions that, in our judgement, constitute obstructive conduct[.]”

Barr previously said he disagreed with some of Mueller’s legal theories in the obstruction of justice probe into President Trump. The attorney general is scheduled to testify before the Senate Judiciary Committee on Wednesday, the first time lawmakers will be able to question Barr about the report since its release.