Senate Democrats have referred information concerning the nomination of Brett Kavanaugh to the FBI, they said Thursday, and called for the Judiciary Committee to delay a vote.

“I have received information from an individual concerning the nomination of Brett Kavanaugh to the Supreme Court,” Sen. Dianne Feinstein, D-California, said in a statement. “That individual strongly requested confidentiality, declined to come forward or press the matter further, and I have honored that decision,” she said.

“I have, however, referred the matter to federal investigative authorities,” she added.

Illinois Sen. Dick Durbin said the referral went to the FBI but also did not say what the information contained.

“No idea what they are going to find,” Durbin told CNN. “I think the FBI is the appropriate agency and that’s where it was referred.”

Durbin also said he does not believe the committee should vote on Kavanaugh “until all the information is before the committee.”

In a statement, White House spokesperson Kerri Kupec said Kavanaugh has been “thoroughly and repeatedly vetted” by the FBI for government positions over the past 25 years and accused Democrats of trying to delay the nomination.

“Throughout his confirmation process, Judge Kavanaugh has had 65 meetings with senators — including with Senator Feinstein — sat through over 30 hours of testimony, addressed over 2,000 questions in a public setting and additional questions in a confidential session. Not until the eve of his confirmation has Sen. Feinstein or anyone raised the specter of new ‘information’ about him,” Kupec said.

“Sen. (Chuck) Schumer promised to ‘oppose Judge Kavanaugh’s nomination with everything I have,’ and it appears he is delivering with this 11th hour attempt to delay his confirmation,” she added.

The letter is the latest turn in Kavanaugh’s contentious nomination. The Judiciary Committee officially scheduled its vote on the nomination for September 20, and Republicans hope to have the full Senate vote on the nomination later this month.

Judiciary Chairman Chuck Grassley, R-Iowa, said he has no plans to delay the vote.

“Sen. Grassley is aware of Sen. Feinstein’s referral,” Grassley spokesman George Hartmann said. “At this time, he has not seen the letter in question, and is respecting the request for confidentiality. There’s no plan to change the committee’s consideration of Judge Kavanaugh’s nomination.”

Sen. John Cornyn, R-Texas, said of the FBI referral: “It smacks of desperation to me.”