About one third of Chipotle eateries have stopped offering pork after the chain suspended a supplier for violating its code of standards, 7 Online reported.

"Sorry, no carnitas" signs were plastered in many restaurants to the dismay of customers.

The national chain found out about the violation through a regular audit conducted on Friday, Chipotle Spokesman Chris Arnold said. He said he doesn't know when a chunk of the 1,724 restaurants will be serving pork again.

"This is fundamentally an animal welfare decision, and is rooted in our unwillingness to compromise our standards where animal welfare is concerned," Arnold said, according to NBC News.

Housing for pigs was the main reason for the violation, according to Arnold. Chipotle won't do business with suppliers that house livestock in inhumane conditions without access to the outdoors.

The company also states that it buys from vendors who raise pigs without antibiotics and are fed a vegetarian diet under their "food with integrity" program.

"The standards for all of our Responsibly Raised meats are very high, but the differences in animal welfare are greatest with pork," Arnold said. "Given these stark differences, serving pork from conventionally raised pigs is not an option to us."

Chicken is the most popular food item at the restaurant, and carnitas accounts for between 6 and 7 percent of orders.

Chipotle is marketing its vegan tofu Sofritas as a filling alternative to meat.