The incident led to the business immediately halting production, which resulted in fully cleaning the processing line and sanitising equipment multiple times before operations resumed.
According to US news outlets, video footage emerged of the employee taking off his gloves and urinating against the production, then carrying on working once he had finished.
The employee, who has not been named, has been suspended by the business pending a complete investigation.
Smithfield Foods said it had swiftly taken steps to ensure the safety and quality of its products following an isolated incident.
“The facility and its employees’ immediate response and corrective actions to this isolated incident reflect the company’s commitment to ensuring the safety and quality of its products, said Smithfield Foods’ senior communications manager Lisa Martin.
“The safety and quality of our foods is fundamental to our success as a company, underscoring our mission to provide ‘Good food. Responsibly’.”
Smithfield Foods was recently fined following a trial over alleged damages caused by noise and smell from one of its farms. A federal jury in North Carolina found in favour of 10 neighbours of an eastern North Carolina hog farm owned by Smithfield Foods, awarding them $750,000 in compensatory damages and $50m in punitive damages over complaints of odour and noise from the farm.