Chipotle (NYSE:CMG) is claiming that Australian beef is to blame for the E. Coli outbreak that occurred late last year.

The health hazard led to 45 Chipotle locations being closed in November and December due to the bacteria being present in restaurant ingredients. The Centers for Disease Control (CDC) reported earlier this month that the E. Coli outbreak is over.

The agency investigated the matter and Chipotle claims the bacteria “was most likely from contaminated Australian beef.” 21 people ended up in the hospital from the Chipotle E. coli outbreak.

This information has been reported by “people familiar with Chipotle.” Grass-fed Australian beef has been a relatively new practice for the Mexican chain.

CMG stock is down 2.32% Friday.

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