Democrats feared Attorney General William Barr’s summary of special counsel Robert Mueller’s report did not accurately reflect the findings, and it turns out Mueller sent a letter to AG Barr, saying his summary “did not fully capture the context, nature, and substance,” The Washington Post reported.

The report cites a letter from Mueller to the attorney general in late March after Barr issued his four-page summary of the Mueller report, concluding no conspiracy to assist Russia in its election meddling campaigns and insufficient evidence to move forward on obstruction of justice case against President Donald Trump.

“The summary letter the Department sent to Congress and released to the public late in the afternoon of March 24 did not fully capture the context, nature, and substance of this office’s work, and conclusions,” Mueller wrote, per the Post. “There is now public confusion about critical aspects of the results of our investigation. 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 “degree of dissatisfaction” from Mueller “shocked senior Justice Department officials, according to people familiar with the discussions,” because Mueller had not expressed concerns before the summary and declined to review it before it was released, according to the Post. Also, the Post reported, Mueller had only expressed post-summary concerns to Barr regarding the media’s interpretations of the obstruction of justice part of the probe.

“After the Attorney General received special counsel Mueller’s letter, he called him to discuss it,” a Justice Department spokeswoman said Tuesday, per the Post. “In a cordial and professional conversion, the special counsel emphasized that nothing in the Attorney General’s March 24 letter was inaccurate or misleading. But, he expressed frustration over the lack of context and the resulting media coverage regarding the special counsel’s obstruction analysis. They then discussed whether additional context from the report would be helpful and could be quickly released.

“However, the Attorney General ultimately determined that it would not be productive to release the report in piecemeal fashion. The Attorney General and the special counsel agreed to get the full report out with necessary redactions as expeditiously as possible. The next day, the Attorney General sent a letter to Congress reiterating that his March 24 letter was not intended to be a summary of the report, but instead only stated the special counsel’s principal conclusions, and volunteered to testify before both Senate and House Judiciary Committees on May 1 and 2.”

The letter requested a release of the report with suggested redactions, per the report. AG Barr released the partially redacted report April 18.

The Senate Judiciary Committee will hear testimony for AG Barr on the special counsel process and interactions with Mueller.