From the AP:

Mexican police have arrested 42 immigration agents and other government employees accused of running a network that smuggled illegal immigrants into the United States, officials said Tuesday.

The suspects, arrested in raids last week in 12 of Mexico's 31 states, allegedly smuggled Cubans, Uruguayans, Brazilians, Asians and Central Americans through the southern border and guaranteed them safe passage into the United States. It was unclear how the ring operated in the United States.

Attorney General Rafael Macedo de la Concha said his office was asking U.S. law enforcement agencies for help in determining whether any Americans were involved in the ring...

Those arrested included agents and ex-agents of Mexico's National Immigration Institute, the INM, the very agency Mexico relies on to detect illegal migrants and prevent the country from becoming staging base for migrants from other countries.

Even more chilling was the fact that seven of the 26 INM agents arrested were assigned to Mexico's Grupo Beta, a special force designed to protect immigrants...

For extra fun, flip back and forth between this story and the earlier story "Mexico asks to help oversee U.S. border protection plan."