A Sinn Fein MLA called on the justice minister to begin an inquiry into "a lack of prosecutions for human trafficking", on 7 February 2012.
Proposing a motion on the matter, Caitriona Ruane claimed there was a "critical issue regarding the role of the Public Prosecutions Service (PPS) and the judiciary" and she was also critical of the police.
"I believe they need to do much more to improve the police response," she said.
Ms Ruane also called for an all-Ireland sex offenders register, cross-border cooperation and a public awareness campaign.
She said recent investigations had shown £500,000 was spent every week on prostitution in Northern Ireland and that the PSNI suspected there were about 88 brothels in operation within the province.
In response, justice minister David Ford said action to address the problem was moving forward, "so I'm unsure what an inquiry would add to it".
Instead, he announced plans to introduce two new human trafficking offences to meet the requirements of an EU directive.
These would extend powers to prosecute UK nationals who commit human trafficking offences anywhere in the world and those who traffic UK citizens within the UK.
Mr Ford also said he did not see the benefit in a single sex offender register for Ireland as there were also issues of people moving between Northern Ireland, England, Scotland and Wales.
Justice committee chair Paul Givan said police were dealing with human trafficking and described Ms Ruane's comments that the "police had turned a blind eye to this" as "shameful".
Policing Board member Ross Hussey said the board would continue to support the police in tackling this crime.
The Sinn Fein motion, amended by the Alliance Party, passed unanimously.