A "law enforcement" investigation is likely underway in the multi-state Boar's Head listeria outbreak, based on notices USA TODAY received Thursday and Friday.

The 19-state outbreak has hospitalized 59, including 10 deaths, and the existence of a legal investigation, which USA TODAY learned about through rejected and redacted records requests, likely indicates inquiries for criminal or civil proceedings are in progress, said food safety attorney Bill Marler.

"In my 31 years of dealing with (U.S. Food Safety and Inspection Service), I've never gotten a response like this," said Marler, who previously called for a congressional hearing into the situation. The investigation could be looking into the conduct of the USDA's Food Safety and Inspection Service (FSIS) inspectors in addition to Boar's Head, he said.

The listeria outbreak was first reported by the Centers for Disease Control (CDC) on July 19, prompting product recalls from Boar's Head and an investigation between Boar's Head, FSIS, the CDC and other agencies.

Inspection records obtained via USA TODAY Freedom of Information Act (FOIA) requests previously showed that conditions in the Jarratt, Virginia Boar's Head facility where the outbreak originated were noted as subpar dating back at least to 2022. The documents reported the presence of mold and mildew, insects both dead and alive, leaking water, rust and other deficiencies "that could pose imminent threat to product."

The Jarratt, Virginia plant has since been permanently closed, leaving 500 people without jobs. Boar's Head has also discontinued the production of its liverwurst products, which were believed to be the source of the widespread listeria.

Government investigation into Boar's Head outbreak

USA TODAY became aware of the legal investigation when FSIS denied multiple records requests related to the outbreak, citing an exemption that protects from the disclosure of “records or information compiled for law enforcement purposes."

Under this exemption, records and information can be withheld if they are compiled for law enforcement purposes if the release of this information could "reasonably be expected to interfere with enforcement proceedings," said the denial letter.

FSIS withheld nearly 400 pages of documents requested by USA TODAY, saying the premature release of included information could interfere with enforcement proceedings and "hinder the government’s ability to further control and shape the investigation."

As of now, U.S. officials would not comment on any ongoing investigation. 

"Justice Department policy prohibits the confirmation or denial of the existence of an ongoing investigation," Brian McGinn, a spokesman for the U.S. Attorney’s Office for the Western District of Virginia, told USA TODAY.

FSIS and The Office of the Inspector General (OIG) did not immediately respond to request for comment. Boar's Head declined to comment as the company does not comment on legal matters.

Food safety experts, politicians call for listeria probe

Marler is not the only concerned party calling for a large-scale investigation.

On Thursday, U.S. Senator Richard Blumenthal (D-CT) and U.S. Representative Rosa DeLauro (D-CT-03) called on the USDA and DOJ to consider criminal charges against Boar's Head and to strengthen USDA's Listeria prevention protocols.

“The time for action is long overdue, and we urge your agencies to work together to seek immediate justice for impacted consumers and to prevent this from happening again,” wrote Blumenthal and DeLauro in a press statement. “Moving forward, it is critical that the agency take this matter seriously and take the necessary steps to address the concerns raised by this outbreak."