FBI investigation into Brett Kavanaugh: Who wasn't interviewed and what else we know Kavanaugh and Christine Blasey Ford were not interviewed by the FBI.

As senators on Capitol Hill pore over the FBI background investigation into alleged sexual misconduct of President Trump’s Supreme Court nominee Brett Kavanaugh, questions have emerged over what limits the White House may have placed over the investigation.

Two of the five swing-vote senators on the Kavanaugh nomination -- Susan Collins of Maine and Jeff Flake of Arizona -- both now appear satisfied with the FBI investigation, calling it "very thorough," and more importantly, saying they've seen no new corroborating information within it, while top Democrats are criticizing the report as "incomplete" and "very limited."

Last Friday, the White House gave the FBI a one-week deadline to complete the supplemental background investigation, a time-frame agreed to by Senate Judiciary Republicans and Democrats.

The FBI contacted 10 people in total, and interviewed 9 of those 10, however neither Judge Kavanaugh nor Dr. Christine Blasey Ford were interviewed. The White House has said their public testimony before the Senate Judiciary committee last week and their sworn statements were sufficient. Sen. John Kennedy of Louisiana said Republican senators were told in their briefing on the FBI report that the 10th witness refused to be interviewed.

The FBI was authorized by the White House to interview anyone it wanted to, but with a limited focus on two claims of sexual misconduct against Brett Kavanaugh: one by Dr. Ford, the other by Deborah Ramirez, sources familiar with the investigation said.

Ford testified before Congress last week that Kavanaugh sexually assaulted her when they were both in high school. Ramirez accused Kavanaugh of exposing himself to her at a drunken dormitory party when they both attended Yale. Kavanaugh has vehemently denied those allegations.

Ford's legal team sent a letter Thursday to FBI Director Christopher Wray questioning why his agents did not interview Ford, as well as other witnesses they said would have challenged Kavanaugh’s testimony, including Ford’s husband and her polygraph examiner. They also said Ford would have provided her medical and phone records.

Allegations of sexual misconduct raised by a third woman, Julie Swetnick, were not in the purview of the FBI background investigation because the White House and Senate Judiciary Republicans deemed her testimony non-credible, sources said.

Administration officials said they made clear to the FBI that the supplemental background investigation was not a criminal probe or a "fishing expedition." Neither Kavanaugh’s drinking behavior, nor the truthfulness of his congressional testimony, were express purposes of the eleventh-hour probe.

The majority of the week-long FBI supplemental investigation appeared to have focused on attempting to corroborate Dr. Ford's allegation from high school. Five of the witnesses interviewed by the FBI were related to that time frame, ABC News has confirmed.

The White House specifically requested FBI interviews with four people: Kavanaugh’s high school friends Mark Judge and P.J. Smyth; Leland Keyser, who Ford claimed was at the party where the alleged assault took place; and Ramirez, whose lawyers provided a list of more than 20 additional witnesses to interview. The FBI also interviewed Christopher "Squi" Garrett and Timothy "Timmy" Gaudette, another classmate of Kavanaugh’s who appeared on the July 1 calendar entry. ABC News has not confirmed the identities of the other three individuals the FBI interviewed.

As for Ramirez's allegation, her legal team confirmed that she was interviewed by the FBI for two hours last Sunday, but complained that agents did not take her list of 20 additional potential witnesses seriously. One White House official strongly suggested the FBI contacted at least one other person related to the Yale allegation besides Ramirez, but would not confirm the identity. ABC News has not been able to independently confirm that any of those witnesses had been contacted.

The FBI has declined to comment on the investigation.