NEW YORK (AP) - Chipotle reported a sales plunge of 30 percent for December after a series of food scares at its restaurants and disclosed a federal criminal investigation tied to the sickening of customers has begun.
The company said in a regulatory filing it was asked to produce a broad range of documents tied to a norovirus outbreak this summer at its restaurant in Simi Valley, California, but declined to provide further details.
It said the investigation does not involve a more recent E. coli outbreak tied to its restaurants that sickened people in nine states, or a separate norovirus outbreak in Boston.
The investigation is being conducted by the U.S. Attorney's Office for the Central District of California in conjunction with the Food and Drug Administration's Office of Criminal Investigations, according to a filing with the Securities and Exchange Commission.
A representative for the U.S. Attorney's office declined to comment. Representatives for the FDA did not respond to a request for comment.
The emergence of a criminal investigation after a norovirus outbreak is unusual, said Bill Marler, a food safety lawyer representing Chipotle customers who were sickened in Simi Valley.
Outbreaks at restaurants are typically caused by an infected employee.
Marler couldn't think of a reason for a federal investigation, other than employment violations.
The disclosure of the investigation comes as Chipotle Mexican Grill Inc. reels from E. coli outbreaks in late October and November, which were followed by the sickened customers at a restaurant in Boston in December.
Those cases received far more national media attention than the California incident, and the company's sales have since plunged.