A man has suffered severe head injuries following an assault in Dungiven.
It happened on the Garvagh Road shortly after midnight on Sunday November 12.
Police were contacted after a man, aged in his 40s, was taken to hospital by paramedics following the incident.
A 45-year-old man has been arrested on suspicion of grievous bodily harm and is currently in custody assisting officers with their enquiries.
Detective Sergeant Gary Moore said: “I believe that there were a number of people in the area at the time of this incident and I would ask anyone who witnessed the incident or who has any information which could assist our investigation into this serious assault which has left a man in hospital with very serious head injuries to contact detectives in Coleraine on 101 quoting reference number 49 12/11/17 or Crimestoppers anonymously on 0800 555 111."