It follows an assault that occurred in Coleraine on the evening of Sunday, March 2.
He is currently assisting police with their enquiries.
The assault occurred in the New Market Street area and was reported to police just before 8pm.
A 52 year old man was taken to hospital for treatment to his injuries. His condition is currently described as critical but stable.
Anyone who witnessed this incident or who has any information is asked to contact CID in Coleraine Police Station on 0845 600 8000.
Or if someone would prefer to provide information without giving their details, they can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111.