The Manhattan District Attorney's office has opened a formal investigation into sexual assault allegations leveled against Rep. Eric Swalwell (D-CA), according to multiple reports published Saturday. The development marks a significant escalation of scrutiny surrounding the California congressman, who has represented California's 14th Congressional District since 2013.

Details of the specific allegations have been widely reported across the political spectrum, with the investigation confirming that prosecutors are taking the claims seriously enough to open a formal inquiry. Swalwell has not been charged with any crime, and it is standard practice for investigations to conclude without charges.

The allegations have also prompted a congressional expulsion effort, with at least one effort underway to remove Swalwell from the House of Representatives. Expulsion requires a two-thirds vote of the full House, a high threshold that has rarely been met in U.S. history.

In the political arena, the allegations have begun to reshape Swalwell's standing among supporters. Multiple endorsers have withdrawn their backing following the emergence of the accusations, according to reporting from Axios. Swalwell has been a prominent Democratic voice on national security and judiciary matters and has previously run for president.

The congressman has not yet publicly addressed the Manhattan DA's investigation in detail. The investigation adds a legal dimension to what had previously been handled in the political and media spheres. Legal experts note that a DA investigation does not imply guilt and that the process could take considerable time to unfold.