WASHINGTON — On the morning of April 25, Jose Moreno Serrano pulled his Dodge SUV into a border checkpoint in Arizona, ostensibly on his way to work at the Mexican Consulate in nearby Yuma.

Using his consulate VISA and SENTRI pass — essentially a "fast pass" for frequent border crossers — Moreno quickly moved through security and into the United States at 7:42 a.m.

Less than an hour later, Moreno was arrested by federal officials for transporting 100 pounds of cocaine, hidden in a secret compartment in his SUV.

With a street value of more than $2.7 million, the bust was a significant haul for the Immigration and Customs Enforcement division of the Department of Homeland Security. The arrest of Moreno — a low-level, consulate employee — highlights how deeply entrenched the drug cartels have become on both sides of the border.

Moreno, whose job at the consulate involved working with Mexican nationals involved in the U.S. criminal justice system, would later tell investigators "he was being paid $4,000 for the delivery," which was his second that week.

But court documents show DHS agents had opened an investigation into Moreno in the fall of 2013 and began keeping tabs on his comings and goings across the border.

Sometime between December and March, DHS agents placed a GPS tracking device on Moreno's SUV, at which time they discovered two hidden compartments built into the undercarriage of the vehicle.

Moreno remained under surveillance until the morning of April 25, when according to a DHS source familiar with the case, he deviated from his normal route to work. That aroused the suspicions of the two agents who were following Moreno.

Shortly after 7:45 a.m., the agents, identified in court documents as E. Tolman and F. Gonzalez, pulled Moreno over. They informed him they were conducting an "extended border search" — a legal doctrine that provides law enforcement with more leeway than under traditional search and seizure rules — of his vehicle.

Inside the hidden compartments agents found "several black taped packages … the combined gross weight of the packages is 45.85 kilograms/101.1 pounds," according to the court documents.

According to a Mexican government official Moreno, who worked in a non-diplomatic capacity, had his temporary contract with the consulate terminated after his arrest, and the Mexican government is not providing him with assistance in his pending legal case.

Between 2005 and 2011, 233,000 pounds of cocaine were seized along the southern border.