"Secretary Clinton gave a voluntary interview this morning about her email arrangements while she was Secretary," spokesman Nick Merrill said. "She is pleased to have had the opportunity to assist the Department of Justice in bringing this review to a conclusion. Out of respect for the investigative process, she will not comment further on her interview."
The interview occurred at FBI headquarters in Washington, D.C., and lasted approximately three and a half hours, according to a Clinton aide.
"I was happy I got the opportunity to assist the department and bring this to a conclusion," Clinton said in an interview scheduled to air Sunday on NBC's "Meet the Press."
The presumptive Democratic presidential nominee said she still stands by "my answers that I first gave more than a year ago."
The Justice Department declined to comment, and the FBI did not immediately respond to a request for comment.
The FBI is in the final stages of its email-related investigation, looking at how Clinton and her aides handled classified information when she was secretary of state.
Officials want ample time to review Clinton's interview and compare it to everything they have discovered in the months-long investigations, according to the source.
"Certainly, my meeting with him raises questions and concerns," Lynch acknowledged on Friday. "It has now cast a shadow over how this case may be perceived, no matter how it's resolved. ... [But] it's important to make it clear that that meeting with President Clinton does not have a bearing on how this matter is going to be reviewed, resolved and accepted by me."
She added, however: "I certainly wouldn't do it again."
Both Lynch and Bill Clinton have insisted the meeting was completely "social," focusing on grandchildren, golf, travel, the Brexit vote, “and things like that," as Lynch put it.
Donald Trump kept up his attack on Clinton for her email use, tweeting today that "It is impossible for the FBI not to recommend criminal charges against Hillary Clinton. What she did was wrong!"
ABC News' Mike Levine, Julia Jacobo and Pierre Thomas contributed to this report.