Chipotle hit with subpoena in federal criminal investigation over norovirus

Chipotle was served with a federal grand jury subpoena as part of a criminal investigation tied to a dangerous norovirus outbreak this summer at one of its restaurants in California, the company announced Wednesday.

The subpoena, received last month, requires the company to produce a broad range of documents tied to the restaurant in Simi Valley. 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, the company said.

Chipotle Mexican Grill Inc. has been reeling since an E. coli outbreak linked to its restaurants in late October and November, which was followed by a separate norovirus outbreak at a restaurant in Boston in December. The cases have received far more national media attention than the norovirus outbreak in California.

Chipotle said sales plunged 30 percent in December. The company expects sales to fall 14.6 percent at established locations for the full fourth quarter, marking the first decline since the company went public in 2006.

READ MORE ON FOXNEWS.COM.