In urging survivors to come forwards, the distict attorney’s office said on Saturday: “Our specially trained prosecutors, investigators and counselors are well-equipped to help you in a trauma-informed, survivor-centered manner.”
The investigation came a day after Swalwell said the allegations were “false”.
“For nearly 20 years, I have served the public – as a prosecutor and a congressman and have always protected women,” the married father-of-three added. “I will defend myself with the facts and where necessary bring legal action.”
The first allegation against Swalwell emerged publicly on Friday in the San Francisco Chronicle.
A former staff member told the newspaper that shortly after being hired to work in his district office in Castro Valley, Swalwell began making inappropriate comments, including soliciting her for sex and sending her sexual messages.
The woman alleged to the Chronicle that she had been assaulted twice by Swalwell.
She told the newspaper the first alleged incident happened in September 2019 after they went out for drinks.
She said the second alleged assault was in 2024, when she said she met Swalwell after a charity gala in New York. On both occasions, she said she was too intoxicated to consent.
The BBC has not been able to independently verify her account or identity, but has contacted her attorney for comment.
CNN published accusations from four women who made accusations of sexual misconduct against Swalwell.
His legal team has sent cease-and-desist letters to two of the accusers, according to the broadcaster.
Swalwell said in a video message on Facebook that he wanted the public to hear directly from him and again denied the allegations.
“I do not suggest to you that I am perfect or a saint,” he said. “I’ve certainly made mistakes in judgment in my past. But those mistakes are between me and my wife. And to her, I apologise deeply for putting her in this position.”
Within hours of the accusations surfacing on Friday, Swalwell lost backing for the governor’s race from prominent supporters, including Senator Adam Schiff and House Democratic Leader Hakeem Jeffries.
The allegations have come at a key moment in the wide-open primary race to replace outgoing Governor Gavin Newsom and to lead the nation’s most populous state, just weeks before voters receive mail ballots ahead of the 2 June election.
Among Democratic candidates, Swalwell was projected to be one of the top candidates in a crowded field, according to two opinion polls.