The appropriately named Olive Press has reported 39 people have become infected by norovirus after eating contaminated frozen mussels.
The outbreak occured in Valencia, but the infected batch had already been distributed to Andalucia, the Balearic Islands and nine other regions.
The Spanish Agency for Consumer Affairs, Food Safety and Nutrition has issued a warning to anyone who has bought frozen mussels from the batch to throw them away immediately.
The product is frozen cooked mussels from Galicia, called Mejillón media concha súper, under the Estrella Polar brand.
Any packaging containing the lot number 010DOP-18 should be thrown out.
The European Competent Authorities have also been informed through the Rapid Alert System for Food (RASFF).