Norway -- Four Sandefjord men, aged 21, 31, 25 and 31, were arrested by police and charged with kidnapping, according to dagbladet.no (in Norwegian).
The incident allegedly occurred December 16, 2010 and police said they were still looking for one additional suspect.
The group allegedly kidnapped another man, with connections to a well-known criminal gang (B-gjengen), south of Oslo.
The victim was forced into a car. He was taken to a place in Vestfold county, where he was threatened, beaten up and held captured for several hours.
The four kidnappers all belong to a special "martial arts environment" - a MMA "Fight Club" of sort, with connections to Hells Angels, according to reports.
Police speculates whether the martial arts trained men has been hired by criminals in Oslo to tray and scare others to pay back debt.
The case has been handled by the organiced crime unit in Oslo since december 2010.