By Ariane de Vogue and Jeff Zeleny, CNN

(CNN) -- The FBI spoke with Deborah Ramirez on Sunday in its investigation into Supreme Court nominee Brett Kavanaugh, a source familiar with the matter has told CNN.

Ramirez accused Kavanaugh of exposing himself to her at a party when he was a freshman at Yale, according to an account published in The New Yorker. Kavanaugh has vehemently denied the allegation.

In an interview with the magazine, Ramirez said that she realized if she ever did speak with agents for the FBI, she knew she would be questioned about some lapses in her memory, her drinking at the party and her motivation for coming forward.

The source said Ramirez supplied the FBI on Sunday with the names of witnesses.

The revelation raises the question of whether the FBI would interview the witnesses or whether the scope of the agency's mandate precludes them from doing so.

Christine Blasey Ford, who testified Thursday before the Senate Judiciary Committee about her allegation that Kavanaugh sexually assaulted her when they were both in high school, was not on the initial list of witnesses that Senate Republicans gave to the White House for the FBI to interview for Kavanaugh's re-opened background check, according to two sources familiar with the matter. Kavanaugh was also not on that list. He has repeatedly denied Ford's allegation.

Ford and her lawyers have not heard from the FBI, sources familiar with Ford's legal team have told CNN.

Ford's lawyer, Debra Katz, told The New York Times, "We have not heard from the FBI, despite repeated efforts to speak with them."

Sources familiar with the investigation have said that only four people were expected to be interviewed: Mark Judge, Patrick Smyth, Leland Keyser and Deborah Ramirez. But one of the sources cautioned that the list could expand based on conversations with others.

The reason Ford and Kavanaugh might not need to be interviewed is that their accounts are already known from their sworn testimony before the Senate Judiciary Committee last week, sources said.

President Donald Trump ordered the FBI investigation following a push from Arizona GOP Sen. Jeff Flake on Friday. The investigation is narrow in scope and is limited to one week, although Trump has said the FBI would have "free rein" in the probe.

Ramirez's attorney John Clune said in a statement earlier this weekend that the FBI had reached out to her and that she had agreed to cooperate with the investigation.