Members of the justice committee expressed concern that the minimum sentence for people convicted of human trafficking offences could be as low as six months, on 20 September 2012.
The committee was taking evidence on the parts of the forthcoming criminal justice bill dealing with trafficking.
Simon Rogers from the Department of Justice (DoJ) explained how it was proposed to update current legislation to fulfill the demands of the EU directive on human trafficking.
Areas of concern included cases where a person had been trafficked outside the UK by a British citizen or someone habitually resident in the UK, or where a person had been trafficked entirely within the UK.
Mr Rogers explained that the maximum sentence for anyone convicted of trafficking was 14 years.
Committee chairman Paul Givan of the DUP wanted to know if it was possible to set a minimum sentence.
Mr Rogers said the usual approach was to give the judiciary the freedom to sentence appropriately.
Mr Givan's DUP colleague, Jim Wells, described attending a police presentation where he heard about a young girl being locked and "forced to have sex with 20 men a day".
Mr Wells also asked about a mandatory custodial sentence.
Mr Rogers said the UK maximum sentence of 14 years was higher than the sentence of 10 years laid down in the EU directive.
The Alliance Party's Stewart Dickson was concerned that the maximum sentence for trafficking offences dealt with in the magistrates courts was six months, unlike the rest of the UK where the figure was 12 months.
Mr Rogers said the six-month ceiling existed across all convictions in Northern Ireland magistrates courts.
"We'd be completely rewriting the manual for the judicial system," he said.
Tom Elliott of the UUP and the DUP's Sydney Anderson also expressed concerns about sentencing.
The committee then took evidence from members of the Organised Crime Task Force Immigration and Human Trafficking Sub-group.
Detective Superintendent Philip Marshall of the Police Service explained that 2,800 officers had been trained in dealing with human trafficking.
He said there were a number of "ongoing investigations into organised crime gangs".
Paul Givan asked Simon Rogers for the DoJ's view on the possible prohibition of paying for sexual services.
Mr Rogers said he could not comment because officials had not yet put their advice to the minister.
"There are different views of that approach," he added.
Det Supt Marshall referred to the experience in Sweden where a similar ban had been put in place.
He said the law had been introduced to address the matter of street prostitution, but the problem in Northern Ireland lay with off-street prostitution.
"We have to be very careful to compare apples with apples and not apples with pears," he added.