House Homeland Security Subcommittee on Border Security and Enforcement Chairman Clay Higgins, R-La., said some unaccompanied children arriving at the U.S. southern border appear to be drugged. 

"Some children [who] arrive at the border appear to be drugged, preventing law enforcement authorities from properly questioning them about those they're traveling with," Higgins said Tuesday.

The committee held a hearing on the thousands of migrant children that have gone missing under the Biden-Harris administration. 

Witnesses include Health and Human Services whistleblower Tara Rodas, Kathy Larin from the U.S. Government Accountability Office, retired Deputy Patrol Agent JJ Carrell and human trafficking consultant Alicia Hopper. 

"I think in America we should ask ourselves why are so many children arriving at the border afraid and alone... sometimes in the hands of an unconfirmed relative with no apparent indications of a family connection," Higgins said during opening remarks. 

He added that sometimes these children have arbitrary phone numbers and addresses on their arms, as if they were "arriving at someone's warehouse or doorstep."

Last year it was reported that the Biden administration lost track of about 85,000 children who entered the U.S. without an adult.