The man is said to have run a criminal network in Gothenburg for many years, according to several media outlets. He was arrested in Vienna, Austria, in December last year.
He was suspected of a shooting at a tram stop in September 2012 in which a man was shot dead.
"The reason for my decision is that despite a thorough investigation, the evidence has not reached such strength that sufficient grounds for prosecution exist or can be expected to be achieved," says Chief Prosecutor Per-Erik Rinsell in a press release.
The man is still a suspect in a case of aggravated embezzlement. Charges are expected to be brought in the near future.
