PHOENIX – The illegal immigrants being sneaked into the country were allegedly given phony $30 tickets and receipts for a van ride. And they were warned that if the van got pulled over by police, they should show the receipt.

Federal investigators Thursday raided five shuttle-van services in Tucson and Phoenix and accused them of knowingly helping to smuggle tens of thousands of illegal immigrants into the U.S. over four years. A total of 49 van operators and alleged smugglers from Mexico and the U.S. were arrested.

The raids exposed a piece of what authorities say is a network of seemingly legitimate businesses that sneak people across the Mexican border.

“The goal of the shuttle operators is to make the aliens look like any other person who would get into a shuttle, like they were going from the airport to their hotel or on a journey around the Southwest,” said Matthew Allen, chief of investigations for U.S. Immigration and Customs Enforcement in Arizona, the busiest illegal gateway into the United States.

Investigators said the shuttle-van companies served illegal immigrants who had already slipped into the country by walking dozens of miles through the desert past Border Patrol checkpoints. They got in vans in Tucson and headed to Phoenix.

Once they reach Phoenix, illegal immigrants are usually home free. From there, they typically make their way to jobs all over the country.