African women, mainly Nigerian, accounted for two-thirds of all victims of sex trafficking assisted by an Irish charity last year.
Ruhama said organised crime ran the “bulk of prostitution” in Ireland and that the charity worked with 92 victims of trafficking in 2016.
It said the women were from 23 different nationalities, with 60 coming from Africa — 43 from Nigeria alone.
The scale of trafficking involving Nigeria women was highlighted last week by the EU police agency Europol.
It released details of a major operation which saw 24 members of an organised criminal group, involved in trafficking young Nigerian women for sexual exploitation, arrested in Spain while the network’s ring leader was apprehended in Finland.
Europol said the network had a “big infrastructure” in Nigeria, as well as links in other countries, and it controlled the whole trafficking process: from recruiting the victims in Nigeria, to smuggling them into Europe and forcing them into prostitution.
In Spain, the victims were instructed to request international protection and asylum, so they could “work for the criminal organisation without problems in the event of being identified by the police”.
Europol said the gang provided the victims with fraudulent documents to request asylum.
In its annual report for 2016, Ruhama said there was a growing demand for its services.
“Whilst prostitution has largely moved off the streets into anonymous apartments, massage parlours and suburban housing estates, it seems to have become quite pervasive in Ireland over the past few years,” said Ruhama chairman Colm O’Dwyer.
“It is worth reiterating Ruhama’s view that prostitution and trafficking are inextricably linked. Women (and girls) are frequently brought to Ireland into brothels under false pretences, by blackmail and by coercion.”
Ruhama CEO Sarah Benson said the “bulk of prostitution” in Ireland was run by organised crime gangs, who profited from the sexual exploitation of women and girls, particularly in off-street locations.
“These unscrupulous individuals make money from human misery — moving often vulnerable migrant women in a co-ordinated fashion from brothel to brothel across Ireland, with a view to satisfying local sex buyers’ demands,” said Ms Benson.
The report said that, in total, it dealt with 304 women from 37 different countries in 2016.
“Some women fled economic crises, conflict and terrible poverty in the hopes of a better opportunity, only to find themselves on this small island on the other side of the world from their homes — in Ireland’s brothels.”
Of the 304 women, 99 were new victims.
The report said that 222 women required intensive support from Ruhama’s casework service.
Ruhama said that the experiences of these women were “deeply harrowing” and included rape, assault and other forms of psychological, physical and sexual violence.
Ms Benson said important new legal measures had been brought in this year under the Sexual Offences Act 2017, including the criminalisation of the purchase of sex and heavier penalties for those organising or profiting from prostitution.
She said the legislation needed to be “properly enforced” and called for the Garda Protective Services Bureau to be fully resourced.