A 2.5-pound shipment of marijuana was intercepted and followed to Simpson's home as a destination. It had been sent from Eureka, Calif.
Simpson and teammate Anthony Collins were allegedly at the house when the package was delivered.
Authorities say a search of the home turned up six more pounds of marijuana, but no arrests were made.
The case is being investigated by police at the Cincinnati/Northern Kentucky International Airport, along with other local authorities.
The Associated Press contributed to this report.