A County Tyrone man was arrested on suspicion of paying for sexual services during a weekend police operation.
He was detained in the Stewartstown area and is helping detectives with their enquiries.
The operation was part of the PSNI's Modern Slavery and Human Trafficking Unit in which a 57 year old man in the Belfast area was arrested on suspicion of human trafficking for the purpose sexual exploitation, controlling prostitution, brothel keeping and money laundering.
A search was also carried out and a number of electronic devices were seized.
A 27 year old woman has also been arrested in the Antrim area on suspicion of controlling prostitution, brothel keeping and money laundering.
Both of the suspects have been taken to Musgrave Serious Crime Suite for questioning.
A further five men aged 20, 33, 33, 36 and 52 have been arrested at locations across Northern Ireland on suspicion of paying for sexual services. They have been taken into custody and are assisting detectives with their enquiries.
Detective Inspector Mark Bell said: "These arrests are part of a proactive investigation into human trafficking for sexual exploitation in Northern Ireland which has been ongoing for eight months.
"Sexual exploitation is often an unseen crime - often victims are transported to clients' properties so there may not be the obvious case of men coming and going to the one property. "Furthermore, many victims can be afraid to speak out or may be being held captive. However, for some people who are subject to this kind of exploitation, they may not think of themselves as victims. They may be vulnerable and have been manipulated into having sex for money, often controlled and coerced into passing over some of the profits to another person who ultimately lines their pockets as a result of the exploitation.
"I want to appeal to victims to come forward to police. I want you to get the help and support that you need. Perhaps you are in this position but don't think that you are being exploited. I'd urge you to have a think about the people around you and if there is anyone who is pushing you in a certain direction or financially benefiting from your activities, please make contact with the police."