Law enforcement officers inspect a drug tunnel found in a warehouse in Otay Mesa, Calif., April 3, 2014, in this handout photo released to Reuters on April 4, 2014. U.S. federal agents have uncovered two drug-smuggling tunnels underneath the U.S.-Mexico border, both surfacing in San Diego-area warehouses and equipped with rail systems for moving contraband, officials said on Friday. The discovery led to the arrest of a 73-year-old woman accused of running one of the warehouses connected to a drug smuggling operation, according to a joint news release by four federal agencies. REUTERS/Immigration and Customs Enforcement/Handout via Reuters

Three drug tunnels, one extremely sophisticated, were discovered by American and Mexican officials in the San Diego-Tijuana region this week.

Two of the three tunnels were found just around the corner from one another and are believed to be run by the same person, 73-year-old Chula Vista resident Gladdys Rodriguez. She is being held without bail and charged with conspiracy to maintain a drug-involved premises.

One tunnel, discovered on Tuesday, is a railed-lined passageway outfitted with a 70- foot vertical shaft and pulley system for hauling up contraband at the delivery location. It goes 600 yards between a commercial building in Tijuana and one in a San Diego industrial park.

The second was found on Thursday and is more sophisticated. It had a multilevel electric rail system, ventilation, and runs 700 yards long.

Friends of Rodriguez were in disbelief over Rodriguez’s potential connections to the tunnels. Rodriguez runs an immigration and tax company called G&R Services, according to NBC 7 San Diego.

"It’s impossible. She could not, she would not be involved. And I could give my life for her and she would not,” said Rodriguez’s friend Cathy Welsh, “I witness her life. I take care of her dog. She just goes to her office every day.”

On Friday, U.S. and Mexican authorities found yet another tunnel outside Nogales, Arizona, this time incomplete. It was discovered in a backyard shed of a residence on the Mexican side of the border. It runs 60 feet in Mexico and 389 feet in the U.S., and ends in a canyon area of Arizona. It is the fourth tunnel discovered in Nogales, Ariz., in the fiscal year 2014.

No illegal drugs were found on any of the properties where the tunnels were dug. No one has been charged in the Nogales case yet.