FBI officers raided a California home in connection with the investigation into former US Congressman Eric Swalwell, US media reports.

Swalwell, 45, dropped out of California's governor's race earlier this year and gave up his seat in the House of Representatives after allegations of sexual misconduct while in office emerged.

In August, the FBI stopped the former Democratic lawmaker at an airport, seized his electronic devices and raided his Washington DC home as part of the investigation into those allegations.

Swalwell has in the past denied any wrongdoing and his attorney has called them "fabricated".

"These accusations are false, fabricated, and deeply offensive - a calculated and transparent political hit job," his attorney Sara Azari said around the time they were first reported.

The BBC has contacted Swalwell's lawyer for comment.

In a statement, the justice department said only that "early this morning the FBI conducted an operation in the Los Angeles region related to an ongoing criminal investigation. We have no further comment."

Swalwell has faced allegations from multiple women, including that he raped one victim while she was too intoxicated to respond and that he sent women unsolicited nude photographs.

He is also facing separate probes in New York City and Los Angeles regarding the allegations.

Once a high-profile Democrat that had become a fixture of cable news shows criticising President Donald Trump - and briefly considered a likely future governor of California - Swalwell was abruptly forced to end his gubernatorial bid after the allegations surfaced.

The House ethics committee had also begun its own investigation, which ended once Swalwell left Congress.

Additionally, the White House in August declassified documents from a separate, unrelated FBI investigation into his alleged relationship with a suspected Chinese spy.

Many of those details regarding his 2015 relationship with Christine Fang were already known, and he never faced any related charges.