Mara Jess Fernndez Calvo, 46, ordered a rice and morchella fungi dish at RiFF restaurant in the city on Saturday, according to The Telegraph .
She later died in her home on Sunday morning after suffering from bouts of vomiting and diarrhoea, Spanish newspaper El Pas reported.
An investigation has been opened up to determine whether the cause of death was poisoning or asphyxiation from particles of vomit in her lungs.
The victim wasn't the only one to get to sick her husband, 12-year-old son, and 16 other patrons also experienced symptoms of food poisoning.
"We've conducted a primary inspection of the establishment and everything appears to be normal," explained regional health chief Ana Barcel.
"Analytical tests will now be carried out on the food products."
Morchella fungi, also known as true morels, are considered a delicacy by some chefs but can be poisonous if eaten raw.
The Telegraph reported that inspectors may check if "false morels" morchella's lookalike, highly poisonous cousins were served accidentally.
Public health officials inspected the restaurant on Monday but did not find any problems that could have contributed to the food poisoning, El Pasreported.
"We will have to wait for the autopsy to be carried out on the woman before we can determine whether it was the ingestion of a food that directly caused her death, or whether it prompted a state that led to this fatal outcome, or if she had an existing condition," Barcel said.
In a statement obtained by El Pas, the German owner of RiFF, Bernd H. Knller said that he had decided to close the restaurant pending the results of the investigation.
"I have offered my complete cooperation to the Valencian health authority from the very start in order to clear up the facts, with the hope that we can establish the causes as soon as possible."
He added: "Regardless of what caused the situation, I want to convey my deep regret for what happened, and I hope all of the facts will be clarified shortly."
RiFF did not immediately respond to INSIDER's request for comment.
The Valencian restaurant opened up in 2001 and achieved a Michelin star in 2009. The Michelin guide calls the restaurant: "A centrally located and meticulously appointed restaurant with a studied minimalist-inspired look."
