Speaking to the Sunday Tribune, Conor Lenihan said:

"The most sinister aspect of trafficking and trafficking networks is that there is considerable evidence from the UN crime organisation and police forces worldwide that trafficking networks have substantially replaced drug networks.

"The drug networks have been overtaken because there is more money to be made in trafficking."

Lenihan said he has previously met women who have been trafficked. "I spoke to a number of women who have got in here for between 1,500 and 3,000."

He added he was aware of women being used as prostitutes in brothels after being trafficked and described it as an "awful situation." However, trafficking is not as big a problem in Ireland as it is in other countries, he said.

The majority of people who arrive in Ireland seeking asylum have been trafficked.

Only a small percentage are then forced into prostitution or domestic servitude . . . most pay the traffickers a fee and are provided with false documents to enter the country.

The Immigrant Council of Ireland (ICI) has warned that the number of women and children brought here and forced into the Irish commercial sex trade is bigger than the number of cases coming to the attention of the authorities. To combat this, the ICI is commissioning major research into the extent, causes and best ways to respond to trafficking of women and children into Ireland for sexual exploitation.

A US State Department report into trafficking, released earlier this year, identified Ireland as a potential destination country for women and children trafficked from eastern Europe, Africa, Latin America and Asia.

"The scale of trafficking into Ireland is unknown, but the reportedly small number of cases investigated by gardai is believed to be the tip of the iceberg, " according to ICI CEO Denise Charlton.

"The aim of this research is, firstly, to paint an accurate picture of how many women and children are being trafficked into Ireland for the purposes of sexual exploitation and where they are coming from."

Over 100 gardai are currently undergoing specialist training on how to identify trafficking victims who are being used in the sex trade and domestic servitude.

Ruhama, which works with women in prostitution, and the International Organisation for Migration in Ireland (IOM) are currently training representatives from the Garda National Immigration Bureau (GNIB) as well as gardai from all around the country, particularly those working at ports and airports.

The training involves ways to identify victims, understanding their fear of the authorities and recognising sexualised behaviour in children as indicators, according to Ryan Nelson of the IOM.

Ruhama have come into contact with about 200 women who have been trafficked to work in prostitution but believe this is "the tip of the iceberg."

"The true number could be 10 times that. Because many of these women are operating out of apartments and brothels, and as the prostitution trade has gone online, it is much harder for us to come into contact with them, " according to Geraldine Rowley, from Ruhama.

A BBC television documentary aired two weeks ago showed a suspected childtrafficker admitting to smuggling children through Rosslare port. The suspected Bulgarian trafficker has since been arrested.

A spokesman from the garda press office said they were "looking at the allegation" made in the documentary "but have no evidence to prove it as the truth."