The outbreak has led to questions about whether the lockdown was relaxed too soon – and whether the correct protocols were being followed in the restaurant.
Eleven people have tested positive for the virus after visiting a restaurant in Moormerland, Lower Saxony, while 106 are now in quarantine.
Authorities are investigating whether the owners of the restaurant complied with the strict lockdown rules.
Lower Saxony's Minister of Health Carola Reimann told the German Press Agency that it did not appear that rules were broken – therefore there was no need for the lockdown relaxations to be wound back.
“According to the initial findings, the infection is not due to a normal visit to a restaurant, instead a private party was apparently celebrated there,” she said.
Christian Drosten, chief virologist at Berlin’s Charite Hospital, said that only outside areas of restaurants should be used to prevent transmission.
“Windows could be opened, especially in summer, then you could probably also sit inside. But inside you should only work with a distance rule,” Drosten said.