DALLAS (AP) - An 18-year-old American citizen says he lost 26 pounds because he wasn't given enough food during the more than three weeks he was wrongfully held by U.S. border agents.

Francisco Erwin Galicia told The Dallas Morning News that he wasn't allowed to shower and had to sleep under a foil blanket in a packed holding area.

Galicia was detained at a U.S. Border Patrol checkpoint by agents who suspected he was in the U.S. illegally, even though he was carrying a Texas state ID.

Border Patrol and U.S. Immigration and Customs Enforcement detained him for almost a month. He was released Tuesday.

Government inspectors have long warned about the squalid conditions inside Border Patrol holding cells.

The agencies said Wednesday that they're investigating and remain "committed to the fair treatment of migrants in our custody."