An illegal immigrant was caught Friday trying to sneak into the U.S. inside a washing machine at a Texas checkpoint, U.S. Customs and Border Protection said.

The outrageous smuggling operation was uncovered when a K-9 alerted Border Patrol agents to a U-Haul truck that was stopped at the Falfurrias Border Patrol Station in Falfurrias, Texas, Action 4 News reported.

Officials searched the truck and found the man inside of a washing machine - along with four other undocumented immigrants hiding inside of a cardboard box. All of them were offered medical attention, but they declined, the station reported.

A man who was driving the truck and a woman passenger were arrested, and agents handed the case over to Homeland Security Investigations. It was not immediately clear what happened to the stowaways.

Both the man and woman are U.S. citizens, according to ABC 22.