A 43-year-old man questioned by police about the activities of republican vigilante group RAAD has been released.
A PSNI spokesperson said, following the man's release on Saturday evening, a report will be made to the Public Prosecution Service.
He was arrested in Londonderry on Thursday by officers investigating paramilitary shootings in the city.
A 47-year-old man detained during the same operation was released unconditionally on Saturday.