It was at the beginning of April that two men in their 40s were injured in connection with a fight outside in Landskrona. Some form of restraint must have been used and one of the men later died in hospital.
The 21-year-old man was arrested in Belgium a month ago and handed over to Sweden on Wednesday.
Three men are already in custody on suspicion of murder and attempted murder, according to P4. Another person is detained in his absence on suspicion of aiding and abetting the crimes.