A months-long federal investigation has led to the discovery of a sophisticated cross-border tunnel allegedly used to move more than $45 million worth of cocaine from Mexico into the United States , resulting in charges against four individuals accused of participating in the operation.

According to federal prosecutors, investigators with Homeland Security Investigations' Tunnel Task Force began monitoring a business known as Buy 4 Less in Otay Mesa, California, in late 2025 after observing activity that appeared inconsistent with a typical retail operation .…