It said that the allegation came to the attention of Democratic senators through a civil rights lawyer. They could also use Republican staff attorneys on the committee.
Republicans, with a 51-49 Senate majority, can confirm Kavanaugh if they stay united.
Plus, by acquiescing to an FBI investigation, Republicans would be acknowledging the opposite of what they spent all last week implicitly telegraphing: that Ford's allegation is serious enough for the Senate to examine it but not serious enough to bring in a law enforcement agency. They include Kavanaugh's friend, Mike Judge, who Ford says was in the room when the alleged sexual attack occurred.
How that could backfire for Republicans: What if Ramirez and her lawyer find more people to corroborate her story?
The New York Times and Washington Post have stories.
In a statement provided by the White House, he said the event "did not happen" and that the allegation was "a smear, plain and simple".
Scrambling to respond, the White House and Kavanaugh issued swift denials of the report.
Republicans grew frustrated as Ms Ford's lawyers insisted on a hearing next Thursday rather than Monday or even Wednesday and made other requests, some of which the committee chairman, Senator Chuck Grassley rejected.
Stranded naval commander to be rescued in 16 hours, says Indian Navy
It had also said other entrants were asked to make towards Tomy's position if possible, and added that the weather was extreme. McGuckin's yacht Hanley Energy Endurance, was also dismasted 90 miles to the SW of Thuriya , is the nearest vessel.
Prior to Sunday, Christine Blasey Ford, a California professor, had accused Kavanaugh of sexually assaulting her when they were teenagers at a high school party.
However, one former classmate remembered hearing about the incident from another, and independently corroborated numerous details offered by Ms Ramirez.
Even before the latest turns, the carefully negotiated hearing at the Senate Judiciary Committee with Kavanaugh and Ford carried echoes of the Anita Hill hearings in 1991.
Kavanaugh has called Ford's allegation "completely false" and said in a statement provided by the White House on Sunday night the incident described by Ramirez "did not happen".
Trump, at the United Nations in NY, declared that Kavanaugh is "outstanding", and added, "I am with him all the way".
The potentially explosive hearing, set against a backdrop of the #MeToo movement fighting sexual harassment and assault, comes just weeks before November 6 congressional elections in which Democrats are trying to take control of Congress from Trump's fellow Republicans. The anti-sexual-harassment organization Times Up tweeted on Sunday that "WOMEN MUST BE HEARD" in a "MOMENT OF SOLIDARITY" with Kavanaugh's accusers, Christine Blasey Ford and Deborah Ramirez.
"I remember hearing and being mortified that this was out there", she said.
The White House is standing behind the president's nominee, saying this is the latest claim in a "coordinated smear campaign by the Democrats created to tear down a good man".
US Capitol Police prepare to arrest demonstrators as they protest against the nomination of Judge Brett Kavanaugh to be a Supreme Court Justice outside of the office of US Senator Susan Collins, Republican of ME, on Capitol Hill in Washington, DC, September 24, 2018.