Federal agents confiscated over a ton of marijuana smuggled into the United States via a cross-border tunnel, federal prosecutors say.
The US agents arrested four people and uncovered 3,000 pounds of marijuana after monitoring a drug smuggling ring that had tunneled from Mexico into the southern California town of Calexico.
The secret tunnel is the twelfth underground passage found along the California-Mexican border since 2006.
"For the builders, the financiers and the operators of these passageways, there is no light at the end of the tunnel," said Laura Duffy, US attorney for Southern California.
The 400-yard tunnel connected a quaint, three-bedroom house in Calexico to a restaurant in El Sarape, Mexico. Federal investigators had been monitoring construction for several months, Ms. Duffy said. Smugglers had purchased the US land in April and by December the house was wiretapped and monitored.
"This house and tunnel were constructed under the watchful eye of law enforcement," Duffy said.
Federal agents also monitored four suspects related to the smuggling operation, as well as a second house, believed to be where drugs would be stored until they could be picked up by drivers. The agents waited to move on the suspects until the first shipment of marijuana arrived.
On March 7, agents seized 1,350 pounds of marijuana in the Los Angeles area that authorities say has been linked back to the secret tunnel. The seizure green-lit the arrests of the four suspects.
On Tuesday, two women were arrested in Arizona in connection with the drug smuggling ring, one of whom was the purchaser of the Calexico property, prosecutors say.
On Wednesday, two men were arrested in Calexico. One was in the house that disguised the tunnel and the second was in the suspected safe house. Agents recovered another 1,532 pounds of marijuana from the tunnel.
The Calexico tunnel was the first discovered in the area in a decade, although the use of a tunnel to smuggle drugs is common throughout the US-Mexican border. More than 75 drug tunnels have been discovered along the border in the last five years.
The most recent tunnel was bare compared to similar discoveries. It lacked lighting, rail cars, and hydraulic lifts, all of which have been discovered in other tunnels, Sherri Hobson, assistant US attorney, told the AP.
This report includes material from The Associated Press and Reuters.