The U.S. Department of Justice (DOJ) has opened an investigation into Blue Bell Creameries, CBS News reported Tuesday. Attorneys from DOJ’s Consumer Protection Branch, the same unit that prosecuted Peanut Corporation of America executives, was reported to be in charge of the probe. The investigation is being lead by Patrick Hearn, the USAA who prosecuted the executives of the Peanut Corporation of America.

Blue Bell earlier this year was linked to a Listeria outbreak that resulted in three deaths. The company shutdown all three of its production facilities and recalled its regionally popular ice cream. It has only recently been returning to the market on a staged basis.

The food safety investigation by the U.S. Food and Drug Administration found Blue Bell’s Listeria contamination was reported to company officials as early as 2013 along with other in-plant sanitation problems, including water getting into production facilities.

The challenge for the federal criminal investigation is to determine what Bell Blue executives actually knew and when they knew it. Stewart Parnell, PCA’s executive officer, sent emails with orders to “just ship em” when he knew peanut products were contaminated with Salmonella. Parnell was sentenced to 28 years in prison, and his peanut broker brother was sentenced to 20 years.

Blue Bell has not responded to reports of the criminal inquiry. Blue Bell manufactures ice cream in as many as 60 flavors in Alabama, Oklahoma, and Texas.