“He is no longer suspected of any crime,” Mats Nylén, spokesman for Södertörn police, told TT after the man was released on Sunday afternoon.
According to Nylén nobody else has been arrested and police currently have no suspects for the crime. No weapon has been found.
A further five people were injured in the incident. Four of them have been contacted by the police, but have chosen not to say what happened.
“They’re not always so interested in getting the police’s help,” said Nylén.
The knife attack happened at around half past one on Saturday morning outside the Alby Värdshus restaurant, following a row between two armed gangs.
The dead man was said by police to have been born in 1968. Another man of the same age was taken to Karolinska University Hospital in Huddinge with serious but not life-threatening injuries. Another four men sustained superficial injuries.
A number of the men were known to the police, but only for petty offences.