The leader of a prominent conservative research organization who suggested that Christine Blasey Ford mistakenly accused Judge Brett M. Kavanaugh of sexually assaulting her while in high school, and who built a case against one of his classmates, will take a leave of absence from the organization, its board announced on Sunday.

Edward Whelan, the president of the Ethics and Public Policy Center and a friend of Judge Kavanaugh, offered his resignation after the organization’s board of directors convened a special meeting on Friday, officials said in a statement. But the board did not accept it, choosing instead to place him on leave.

The board’s brief statement did not specify how long Mr. Whelan would be absent or when the leave would begin, saying only, “The board will meet in a month to review the situation.” The board said that Mr. Whelan had led the organization “with integrity and excellence for many years” and noted that he had apologized and deleted a string of tweets that contained the bizarre alternative explanation to the allegations presented by Dr. Blasey.