PUTNAM COUNTY, IND. (WOWO) Indiana State Police say a routine traffic stop on Interstate 70 turned into a major drug bust in Putnam County.

Troopers say they pulled over a semi-truck traveling eastbound near Cloverdale for speeding. During the stop, officers observed what they described as indicators of possible criminal activity and requested permission to search the vehicle according to CBS-4.

Investigators say that search led to the discovery of 178 kilograms, or nearly 400 pounds, of a substance suspected to be cocaine hidden inside the trailer. Authorities estimate the street value of the drugs at around 9 million dollars.

Police arrested the driver, identified as a 27-year-old man from California, at the scene. He is facing preliminary felony charges related to dealing and possession of a narcotic drug.

According to Indiana State Police, the arrest was made by the department’s interdiction unit, which focuses on stopping illegal drugs and contraband along major highways before they reach communities.