Forty-five potential trafficking victims were discovered in Northern Ireland last year.
They claimed they were subjected to domestic servitude, labour or sexual exploitation, the National Crime Agency (NCA) said.
At least one case involved a girl from outside the UK who alleged she was sexually exploited.
Staff at Belfast International Airport have been trained in spotting those affected by a human rights organisation called the International Justice Mission (IJM).
IJM UK chief executive Terry Tennens said: "The vast majority of trafficking victims come from backgrounds of poverty, which makes women and girls especially susceptible to traffickers' schemes of deception.
“They are more likely to accept a fraudulent job offer or an insincere marriage proposal that involves moving to another location or country.”
A Belfast-based academic at a recent Co Down conference on labour exploitation said official figures represented the tip of the iceberg.
An NCA report - National Referral Mechanism Statistics End of Year Summary 2014 - disclosed that last year, 45 referrals were made for potential victims of trafficking first encountered in Northern Ireland.
That represented a 10 per cent increase on the previous year and 2 per cent of the UK total.
A total of 37 referrals were for adults and eight for minors.
At least one case involved potential sexual exploitation of a girl.
Half the victims came from Romania, 10 from China and others from Albania, Vietnam and Lithuania.
They were referred by immigration officers, Belfast City and Cookstown local councils, the PSNI and the Northern Health and Social Care Trust.
International Justice Mission works around the world tackling issues of violence, including human trafficking.
It has worked over the past 18 years taking on individual cases of trafficking: investigating, rescuing victims and pursuing criminal convictions against traffickers.
In an effort to improve the UK Border Force’s response to trafficking, Belfast International Airport has received training from IJM and local authorities.
Individual Border Force members who participated in training in late 2014 conceded that detecting trafficking at the border was very difficult, according to the IJM.
It said: “This is due to the fact that many potential victims do not even realise that they are victims of trafficking until after they have passed the border.
“Training by IJM and other NGOs to help spot the signs of trafficking is therefore crucial in improving the Border Force’s response to trafficking.”
Last year, IJM trained more than 18,900 police, prosecutors, government officials and community members worldwide to be able to recognise and combat all forms of violent crimes in their communities - including human trafficking.
PA