US media reports indicate the raid is the latest development in the federal investigation into the 45-year-old former Democratic lawmaker. In August, the FBI stopped Swalwell at an airport, seized his electronic devices and searched his Washington DC home as part of the same inquiry.
Swalwell has denied any wrongdoing. His attorney, Sara Azari, has called the allegations a "calculated and transparent political hit job". At the time the accusations first emerged, she said in a statement: "These accusations are false, fabricated, and deeply offensive."
The allegations against Swalwell include that he raped one woman while she was too intoxicated to consent and that he sent unsolicited nude photographs to other women.
The BBC has contacted Swalwell's lawyer and the US Department of Justice for comment. The investigation remains ongoing.