A 52-year-old man has been arrested as part of an investigation into human trafficking.
He was detained in Londonderry on Wednesday morning and has been taken to Coleraine for questioning.
Three properties in Derry were also searched as part of the police operation.
Detective Inspector Mark Bell, from the Police Service of Northern Ireland serious crime branch, said inquiries were continuing.
Murder investigation launched following death of man in Coleraine
Man arrested over threats to elected representatives
Teachers’ unions welcome pay increase while pledging to tackle workload
Minister to explore if he can enforce use of Ulster Banner at Commonwealth Games