US finds 'sophisticated' border tunnel

US authorities have found a
US authorities have found a "sophisticated" tunnel running under the US-Mexico border.

An incomplete tunnel found stretching from Arizona to Mexico appears to be "the most sophisticated" migrant smuggling tunnel in US history, authorities say.

The tunnel intended for smuggling ran from San Luis, Arizona, to a Mexican neighbourhood and had a ventilation system, water lines, electrical wiring, a rail system and extensive reinforcement, federal officials said on Thursday.

"This appears to be the most sophisticated tunnel in US history, and certainly the most sophisticated I've seen in my career," said Carl E. Landrum, acting chief patrol agent with the Border Patrol's Yuma Sector.

Homeland Security Investigations found the tunnel in late July. A camera was sent 7.6 metres underground after federal agents discovered a sinkhole in the area of a tunnel investigation, authorities said.

Photos show the tunnel measured about 1 metre wide and 1.2 metres high, according to a US Immigration and Customs Enforcement news release.

Australian Associated Press