The year is not off to a good start for Chipotle. In the wake of several disease outbreaks, the popular Mexican restaurant chain has now been served a federal subpoena and is under criminal investigation.

According to the Associated Press, Chipotle was served the subpoena last month in response to an August outbreak of norovirus at one of the chain’s California locations.

Doug Beach, a manager of the food program at Ventura County's Environmental Health Division, explained reports of illnesses began to come in on Aug. 18, prompting the location to close down temporarily the following Friday. The county was not alerted to the illnesses until the next day, at which point the restaurant had already re-opened. 

The oubreak was just one of several impacting Chipotle restaurants in 2015. Hundreds of people were sickened by E. coli or norovirus in multiple outbreaks reported from coast to coast. Chipotle has acknowledged it saw sales plunge by 30 percent last month in the aftermath of the outbreaks.

The Chicago Tribune adds in an article here 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 subpoena involves a “broad range” of documents.

Bill Marler, a food safety lawyer representing Chipotle customers who were sickened in the August outbreak, told reporters a criminal investigation following a norovirus outbreak is unusual.

This isn’t the first lawsuit Chipotle has faced over the last several months. In July 2015, the law firm Kaplan Fox & Kilsheimer LLP, filed a lawsuit against Chipotle on behalf of “all California consumers” who purchased food from Chipotle since the company made its GMO-free marketing push earlier in the year.

The law firm alleges Chipotle violated the California Consumer Legal Remedies Act, the California False Advertising Law, and the California Unfair Competition Law by misleading its customers with GMO-free advertising.

See, “Chipotle misled customers? Naturally!”