Aftonbladet reported earlier on Wednesday that the restaurant has temporarily closed after alarm about food poisoning.
At least three of the people who sought care have been affected by sepsis caused by listeria infection, confirms Smittskydd Stockholm to several media.
The authority has sent letters to other guests who visited the restaurant around the current dates.
The guests who fell ill are said to have eaten a tasting menu with 14 dishes. It is still unknown what is behind the poisoning. The restaurant is closing during the investigation but is expected to be able to open again next week.
Stockholm's environmental administration has received 60 reports of suspected food poisoning at the current restaurant.
