A man is in a critical condition after being assaulted last Saturday in Limavady.
Police received a report at around 3 am of a serious assault on Irish Green Street by another man.
The 22-year-old also had his phone and house keys stolen.
Detectives are working to establish the circumstances surrounding the incident and are keen to speak to a 34-year-old man.
Anyone who believes they have information or footage of the attack is asked to contact the police.
