Story highlights Blue Bell under federal criminal investigation for response to listeria contamination

Three died from contaminated Blue Bell products, more became seriously ill

A CDC investigation showed the outbreak dated back five years

(CNN) Blue Bell Creameries is under criminal investigation by the U.S. Department of Justice for its handling of the ice cream contamination linked to 10 reported cases of listeriosis, a U.S. official has confirmed to CNN. Three of those believed to be sickened by Blue Bell frozen treats died.

Prosecutors are examining whether company executives committed wrongdoing in their handling of the outbreak.

Blue Bell Creameries has not responded to CNN's request for comment.

After weeks of gradual recalls, Blue Bell recalled all its ice cream, frozen yogurt, sherbet and other frozen treats sold in 23 states on April, 20, 2015, after it said listeria was found on the lid of a food service cup the month before. However, an investigation by the Centers for Disease Control and Prevention showed the listeria outbreak dated back to 2010.

The agency connected patients from 2010-2015 to the current outbreak through comparisons to a database of bacteria DNA