Last Saturday, María Jesús Fernández Calvo, her husband, and their 12-year-old son had lunch at RiFF, a Michelin-starred restaurant in Valencia, Spain. The family of three had the tasting menu, which included one course with morchella, or morel mushrooms. By that evening, all three of them experienced diarrhea and vomiting. By Sunday morning, 46-year-old María Jesús was dead.
By Thursday morning, Las Provincias had reported that at least 29 other recent RiFF diners have also fallen ill. The Ministry of Health has opened an investigation into the causes of this widespread illness, and Food Safety inspectors have collected samples of the foods and ingredients that were part of the restaurant’s tasting menu; they have been sent to Spain’s National Institute of Toxicology and Forensic Science in Madrid for further analysis.
“It would be irresponsible to establish the origin and the cause [until the analysis is complete],” regional health official Ana Barceló told the news outlet. “We don’t know if the death has a direct relationship. We must be cautious and wait for the tests to end.” She added that until they know what raw food or ingredient might’ve been the cause, “we cannot generate alarm between suppliers and other restaurants.”
When inspectors visited the restaurant on Monday, they did not identify any obvious causes for the suspected food poisoning, which is partially why RiFF is closed until further notice. “Regardless of the reason that may have caused this situation, I want to convey my deep regret for what happened, hoping that soon all these facts can be clarified,” owner and head chef Bernd Knöller said in a statement obtained by The Independent. “I have made the decision that the restaurant remains closed until the causes of what happened are established and the activity can be resumed with full guarantees for both staff and all customers.”
Gerardo Gómez and his wife Marialejandra Portal visited Valencia last weekend, and also had a meal at RiFF. They told Las Provincias that they were sick less than an hour after they paid their check. “We didn’t notice anything strange in any of the dishes, or think that something could be wrong. But after forty minutes of leaving the restaurant we started to feel nauseous,” Gómez said. “We vomited three or four times each and we also had to go to the bathroom a couple of times, but after three hours we were already recovering.”
He also said that they would have no problem eating at the restaurant again, although he added that they’ll “be more comfortable when we know the outcome of the investigation.”
Although Barceló has not yet confirmed that morel mushrooms were the cause of the food poisoning—and of María Jesús’ death—it is being investigated as a possibility. In its section on mushroom poisonings, The North American Mycological Society warns that morels can cause “upset” if they are eaten raw or aren’t fully cooked.
Unfortunately, there are morel look-alikes which can cause more than “upset.” Those mushrooms contain a toxin and gastrointestinal irritant called gyromitrin, which can cause headache, diarrhea, and abdominal pain, and in rare cases, can lead to convulsions, coma, or death.
Bernd Knöller opened RiFF in September 2001, and it was awarded its Michelin star eight years later. It has also earned two Repsol Suns (out of a possible three) from the The Association of Friends of the Spanish Royal Academy of Gastronomy and the Good Food Guild. “The owner-chef, who despite being German considers himself Valencian, conjures up innovative cuisine,” Michelin’s inspectors wrote of the restaurant. “This is based around the highest quality, seasonal, local products to create successful culinary combinations and interesting set menus.”
This article originally appeared on VICE US.