Emergency services in a small town in Germany's far north received a number of calls in quick succession on Saturday night, all from locals suffering extreme nausea and vomiting.

A police spokesman said they soon established a common thread between the patients - each of them had earlier eaten chocolate cake baked by a friend.

Officers tracked down the 42-year-old baker, who allegedly admitted to adding a few drops of cannabis oil to the usual baking ingredients.

Police said he too had eaten a slice, and had to stop their interview with him so that he could throw up.

Six people, aged between 23 and 56, sought treatment after eating the cake. Two women were taken to a local clinic after reportedly suffering "health problems during a walk," police said. Around the same time, a couple in their 50s was rushed to hospital complaining of nausea.

Police said the victims were unaware the baked goods contained cannabis, and they're now investigating whether the 42-year-old man should be charged with grievous bodily harm and drug offenses.

They added that the rest of the offending cake had been seized as evidence.

nm/sms (AFP, dpa)