The move follows reports from some aid agencies that forced prostitution is becoming a growing problem in both the Republic and the North.

The joint committee will work with the police, the voluntary sector and other human rights organisations over the course of their investigation.

"Trafficking in people is a major priority for both commissions as we wish to highlight both the nature of the issue and ways of combatting this exploitation, " according to Maurice Manning, president of the commission in the south.

"It makes perfect sense for us to cooperate. Both commissions are currently working out the details of how we can engage more closely on this issue."

A conference held at Queens University in Belfast last week heard how women who had been trafficked had been forced into prostitution in Northern Ireland.

Some of these women were eventually helped by projects in Dublin, Glasgow and London.

Monica McWilliams, chief commissioner of the Northern Ireland human rights commission said: "Trafficking for the purposes of labour or sexual exploitation is a relatively new issue in Northern Ireland but there are indications that it is occurring. This problem is well-known in other parts of these islands and it is often associated with violence, other serious human rights abuses and organised crime, " she said.

"It is important that the two human rights commissions on the island of Ireland investigate with agencies such as the police, the voluntary sector and other human rights organisations how to combat this modern form of slavery, " she said.

The Irish human rights commission welcomed the recent publication by the government of a legislative scheme on trafficking - The Scheme of the Criminal Justice (Trafficking in Persons and Sexual Offences) Bill 2007. One of the functions of the commission is to comment on legislative measures from a human rights perspective and it has just submitted observations to the minister for justice on this particular scheme.