Prosecutors say Miki Nozawa died Monday following a brawl with the two men at a nightclub near his restaurant on the North Sea resort island of Sylt.
German tabloid newspaper Bild reported the men had refused to pay for a dish of fried rice with vegetables and beef.
The paper described Nozawa as a "star chef" who previously worked in Berlin and Sardinia.
Prosecutors' spokesman Ruediger Meienburg said Friday that an autopsy determined the cause of death was a brain hemorrhage but further tests were needed to determine if the bleeding was due to the fight.
In the meantime, no formal charges have been filed.