Bangladesh, Sept. 1 -- A high-profile international manhunt ended in the Spanish city of Málaga after Spanish police, working closely with German authorities, arrested a fugitive described as Germanys most wanted drug trafficker. The arrest highlights the increasingly sophisticated nature of European organized crime-and the equally sophisticated methods authorities are deploying to dismantle criminal networks operating across borders.

Spanish National Police announced the arrest on August 31, saying the suspect had been detained on August 24 following an intensive investigation involving Spanish and German law-enforcement agencies. His identity has not been publicly disclosed. He was wanted under a European arrest warrant on charges...