The two suspects were arrested on a warrant issued by Norway after a Nigerian woman lodged a complaint against them in Oslo.
Spanish police said the pair promised their victims, who were living in extreme poverty, a job and that they would cover their travel expenses. They would then force them to become prostitutes.
The young Nigerian woman who filed the complaint had herself been lured in 2011 to Spain by a woman who promised her work.
When she arrived in Spain, however, she was kidnapped and held in an apartment on the southern edge of Madrid.
Her abductor then forced her to work as a prostitute in several Spanish cities, as well as Bordeaux in France and finally Oslo, claiming she was owed a 60,000-euro ($66,000) debt).
“The ‘madam’ and her accomplices had control over her, using all methods of aggression and threats and resorting to traditional Juju voodoo practices, including animal sacrifices,” the police said.
In these rites, the victims are forced to take a pledge of obedience, and are then persuaded into believing that they would fall ill or become insane if they fail to obey, according to Amnesty International.
The two suspects were arrested at their home with police finding false identity documents and several objects linked to the rituals there.
Six Nigerians including four women were convicted in France last month over similar charges.
Also in June, Spanish police dismantled a trafficking ring that they said used voodoo rituals to force women into prostitution.