MADRID -- A Spanish magistrate has opened an investigation into whether there is a link between the death of a woman and a meal she ate at a Michelin-starred restaurant in Valencia where officials have identified suspected cases of food poisoning.

A Valencia court statement Friday said the magistrate is awaiting forensic reports and the results of an autopsy. The 46-year-old woman died after eating with her husband and 12-year-old son, who also fell ill, at Restaurant Riff last Saturday.

The Spanish private news agency Europa Press says authorities have detected 29 cases of diarrhea and vomiting among people who recently ate at Restaurant Riff.

Bernd Knoeller, the German owner and head chef of the one-star Riff, temporarily closed the restaurant on Tuesday, saying he was co-operating with authorities.