The latest sweep of arrests is the product of more than two years of investigation, led by the Central Anti-Traficking Office as well as units from the border police in the eastern city of Strasbourg
In November last year, seven suspects, male and female, in and nearby the northeastern city. Another two suspects were taken into custody in Italy.
Investigators now claim there are ties between the kingpins of the trafficking network and several key people in the employ of two churches in Strasbourg - Béthel and Reedeem-Church, both of which have ties to the Nigerian community in the area.
French daily Le Parisien reported on Wednesday that the two churches had served as meeting points for prostitutes, where they were asked to contribute to the community in giving up profits of selling their bodies to the pastor of the Béthel church.
The pastor, originally from Nigeria, has since said he was not aware of how the women's money had been acquired, according to a source close to the investigation quoted in Le Parisien.
The two women detained on June 6th, aged 26 and 32, deny any involvement. one of the "madams" has been kept in detention, while the remaining four have been released following furhter investigation.
The fourth suspect taken into custody is suspected of wiring money to Italy, as well as giving rides to the women selling sex. The 36-year-old is also implicated in helping the women file their asylum papers.
He has, according to reports, admitted to some of the charges presented to him.