Kingsville Police made a surprising discovery on Highway 77 Thursday morning, after pulling over a plumbing van that was heading north.

Police are used to finding drugs, money and weapons in hidden compartments, but not people. According to the Kingsville officers, they found immigrants from Mexico in the van -- two women and one man inside of a compartment. Also insider were two pillows and two bottles of water.

Plumbing and welding equipment filled the van, covering the compartment, meaning that if for any reason they needed to get to the people inside, they would have to remove all of the heavy equipment -- and that's exactly what the police officers did to find the immigrants.

"It was actually a cool day. In their favor, it was a cool day, and when they were taken out of the box, they were sweating," Kingsville Police Officer Daniel Gonzalez said. "The interesting part of this plywood is that you see the holes -- breathing holes. A little bit more ventilation for the people. So this compartment here has a purpose, and the purpose is to smuggle illegal aliens into the United States."

Police said the driver of the van is 25-year old Adam Ray Lopez of Austin. Lopez was arrested and taken to the Kleberg County Jail. He is charged with unlawful use of a criminal instrument and human smuggling.

In the majority of cases where police have found illegal immigrants inside of a vehicle, they have just been in the back of a U-Haul, or just inside the vehicle blending in; but finding immigrants in a compartment is extremely rare.