FBI says it's conducting "court-authorized law enforcement activity" at congressman's Texas home

The FBI is conducting "court-authorized law enforcement activity" at Representative Henry Cuellar's Laredo, Texas, home, the agency confirmed in a short statement Wednesday.

Cuellar's office said in a statement that he will "fully cooperate in any investigation. He is committed to ensuring that justice and the law are upheld." It did not confirm an ongoing investigation by the FBI.

A source familiar with the investigation told CBS News that the activity at Cuellar's home is part of an investigation relating to Azerbaijan and several U.S. businessmen. 

A federal grand jury in Washington is investigating the case, CBS News has confirmed. ABC News first reported the scope of the investigation and the grand jury. 

He is presumably not in Washington, D.C. right now, since he has been voting by proxy in the House, and the proxy letter he has filed with the clerk of the House of Representatives remains active.

Cuellar has represented the Rio Grande Valley's district since 2005. He's a moderate Democrat who is facing a primary challenge from his former intern, immigration attorney Jessica Cisneros; she lost by about four points when she challenged him in 2020. Cuellar won reelection that year by 18 points, but President Joe Biden only won by 5 points, underscoring Democrats' problems along the border in Texas, the Texas Tribune noted. 

In a statement on Thursday, Cisneros's campaign said they are "aware of the news regarding Congressman Cuellar and the active FBI investigation. We are closely watching as this develops. In the meantime, we are focused on our campaign to deliver change to South Texas families and will not be making any additional comments at this time." 

Jeff Pegues, Andres Triay and Aaron Navarro contributed to this report.