British sandwich chain Pret A Manger revealed on Sunday that a second person died after having an allergic reaction to one of its sandwiches.

The company ― which has locations in various parts of the world, including the U.S. ― announced that an unnamed customer died in December 2017 after consuming prepared food that contained a dairy protein, even though it was labeled dairy-free. The sandwich, which was purchased in Bath, England, was a “super-veg rainbow flatbread,” British newspaper Metro reported.

This incident follows the 2016 death of a 15-year-old girl with an allergy to sesame seeds who died after eating a baguette that contained traces of the seed. The product was not marked as containing sesame seeds. The teenager, Natasha Ednan-Laperouse, had purchased the baguette at a Pret A Manger location in London’s Heathrow Airport.

Neil Hall / Reuters The British sandwich chain last week said it would start adding ingredient labels to all of its prepared foods to make them safer.

Last week, the sandwich chain said it would start adding ingredient labels to all of its products and would work with outside groups to push for legal changes to better protect people with allergies.

That decision came after a British coroner’s court last month reached certain conclusions in the inquest into Natasha’s death ― specifically, that Pret A Manger’s product labeling was inadequate. Although the coroner did not find that the company had broken any laws, he held that it had not taken allergen monitoring seriously and noted that it had been warned of allergic reactions to its baguettes six times earlier, The New York Times reported.﻿

Bloomberg via Getty Images The company accused coconut milk brand CoYo of supplying the tainted product that appeared to lead to another customer's death. CoYo has called the allegations "unfounded."

“There was no specific allergen information on the baguette packaging or on the food display cabinet, and Natasha was reassured by that,” coroner Sean Cummings said in his ruling.

As for the latest known death, Pret A Manger blamed its dairy-free yogurt supplier, CoYo, for the dairy protein contamination. It said it has severed ties with CoYo, “is in the process of taking legal action” and promptly stopped selling related products as soon as it became aware of the death.

CoYo, a coconut milk brand, shot back at Pret A Manger on Sunday, denying that it was responsible and calling the allegations “unfounded.”

Though CoYo did have its yogurts recalled in February after a dairy contamination was found, the company said the dairy-free product that it supplied to the sandwich chain in 2017 was not linked to that recall. CoYo said the recalled product was supplied to it by a third party, with whom it no longer works, only in January 2018.

“Pret’s inability to provide us with a batch code, despite several requests, has severely limited our ability to investigate this further,” CoYo said.