Washington (CNN) Special counsel Robert Mueller's team has interviewed White House press secretary Sarah Sanders, she told CNN on Friday.

"The President urged me, like he has everyone in the administration, to fully cooperate with the special counsel. I was happy to voluntarily sit down with them," Sanders said in response to a question from CNN.

The interview is one of the final known interviews by Mueller's team of people who worked in the White House. It was conducted late last year, around the same time as the special counsel interviewed then-White House chief of staff John Kelly, well after a number of other senior officials, including former White House communications director Hope Hicks and former press secretary Sean Spicer, were brought in for questioning.

The White House did not immediately agree to grant the special counsel an interview with Sanders, according to one of the sources. Similarly, as CNN reported in December, White House lawyers initially objected to Mueller's request to interview Kelly, who ultimately responded to a narrow set of questions from special counsel investigators.

While the substance of the interview with Sanders is unclear, one likely area of interest was how Sanders composed statements she made on the podium defending the President regarding the Russia investigation.

Read More