HARLINGEN- A complaint over street racing led to a drug bust in Harlingen.

Police say around 3:00 Sunday afternoon, they were working traffic enforcement on the expressway.

That's when an officer noticed a tractor-trailer tailgating another vehicle.

When the driver of the semi was pulled over, police said he started acting nervous.

During a search of the cab, officers found cocaine stashed inside a duffle bag.

The driver was arrested for possession of a controlled substance.