New panic at White House after briefing on Mueller report: 'There is significant concern' over obstruction
FBI Director Robert Mueller testifies during a House Appropriations Committee hearing on the FBI Budget, on Capitol Hill on March 19, 2013 in Washington, D.C. (UPI/Kevin Dietsch via Creative Commons)

White House officials have reportedly been struck with "significant concern" after they were briefed on special counsel Robert Mueller's Russia investigation report.

ABC's Jonathan Karl revealed on Sunday that officials at the White House now know what's in the Mueller report.

"They have been briefed but I'm told in broad brush strokes," Karl explained. "They've been briefed enough to know that the White House will not invoke executive privilege to try to get further redactions."

"But there is significant concern on the president's team about what will be in this report," he noted.

"Even the stuff that will be un-redacted?" ABC News host George Stephanopoulos asked.

"Yes," Karl clarified. "There is significant concerns about what will be in here -- new information -- on the obstruction of justice question, what the president was doing regarding some of the big questions."

"What worries them most is what [former White House counsel] Don McGahn told the special counsel," he added. "It was reported that he spent 30 hours before the special counsel. I'm told significantly more than 30 hours."

And there is reason for the White House to be concerned. According to Karl, no one on the president's legal team ever debriefed McGahn about what he told the special counsel.

Watch the video below from ABC.