NASHVILLE, Tenn., May 19 -- The Tennessee Bureau of Investigation issued the following news release:

DICKSON COUNTY- A joint investigation led by the Tennessee Bureau of Investigation and the 23rd Judicial District Drug Task Force has resulted in the arrest of four people.

On May 15th, agents identified and searched a semi-truck and trailer with Texas plates in Dickson County. Inside the trailer agents discovered and seized more than 1,500 pounds of suspected methamphetamine and later determined the trailer was being used to transport the shipment from Mexico to Tennessee. The methamphetamine was hidden on pallets, packaged and disguised to look like Alfalfa pellets.

The operation and investigation, which also included the execution of ...