German police are investigating a kebab sauce after it was used in an attack.

Reuters reports that the condiment was thrown at the victim after a dispute over napkins.

When the salesman in Bremen refused to give the customer a napkin, he wiped his hands on the kebab cart. The salesman then threw a ladle of chilli sauce at him.

The victim's eyes became bloodshot and police took a sample of the sauce.

"Legally, the question of whether the spiciness of the kebab sauce constituted 'normal' or grievous bodily harm must be addressed," a police spokesperson said.

Officers are also trying to determine the cause of the argument. Both men could end up facing charges.