By Monday afternoon, the local health and safety authority had received reports from some 593 people who claimed to have fallen ill following a visit to Pizzeria Alcamo.
The pizzeria was closed down by officials on Thursday, just days after the first reports of customers suffering from vomiting, diarrhea and high fever.
It is not yet known whether patrons fell ill as a result of food poisoning or a fast-spreading outbreak of the winter vomiting virus.
The council’s health and safety office has carried out tests on kebab meat, iceberg lettuce and kebab sauce in a bid to isolate the source of the outbreak.
In a statement released on Monday afternoon, Jönköping council said it hoped to be able to present the results of its findings before the coming weekend.