A Texas meat company is being forced to pay up after U.S. federal inmates were unknowingly served pet food.

John Soules Foods Inc., a company that specializes in fajita meat, has agreed to pay $392,000 to the U.S. government after a labelling mistake led to Texas inmates being fed meat meant for animals, according to a press release from the U.S. justice department.

A three-year investigation by U.S. Department of Agriculture found that in late 2006 and early 2007, the company sold raw "beef trimmings" to a wholesaler who agreed to sell the product as pet food. The boxes were not properly labelled, however, and the meat was later re-sold to the Federal Bureau of Prisons for human consumption.

The company has not admitted to any civil or criminal misconduct under the agreement, but it will have to adopt additional procedures to ensure it meets federal food safety standards.

The investigators said there is no evidence that anyone who consumed the "beef trimmings" product suffered any ill effects.

According to its website, John Soules Foods is the "leading fajita processing and marketing company in the U.S." It is based near Tyler, Texas, and employs approximately 500 people.