Originally published on April 7, 2014

U.S. officials uncovered two drug-smuggling tunnels running across the border with Mexico and arrested a 73-year-old woman charged with overseeing their construction, agents for Immigration and Customs Enforcement announced on Friday.

The two tunnels discovered last week were the sixth and the seventh to be found in San Diego's Otay Mesa area in less than four years.

The entrance of the first of the two tunnels, discovered on Tuesday, was found within a warehouse, hidden under boxes of televisions and toys and sealed by a concrete slab.

The small entrance opened to a 15-foot walkway, which led to a 70-foot vertical shaft complete with a half-ton winch and pulley system. The tunnel stretches some 600 yards, ending at another warehouse in Tijuana.

A second 700-yard tunnel equipped with a multi-tiered electric rail system and ventilation equipment was discovered on Thursday in the same area.

No drugs were found in the tunnels at the time of their discovery, and agents cannot tell whether the drugs moved through the tunnels before they were discovered.

Arrested on Tuesday, 73-year-old Glennys Rodriguez denied any connection to the warehouse tunnels despite surveillance evidence showing the contrary. According to a complaint filed by the U.S. Attorney's office, Rodriguez paid a friend to lease one of the warehouses under his name while the tunnels were under construction.