A man suffered a broken arm when he was attacked at a property in Brighton on Monday night (18 February).
The 57-year-old victim was taken by ambulance to the Royal Sussex County Hospital in Brighton for treatment.
A 58-year-old man was arrested on suspicion of assault causing grievous bodily harm (GBH) after the attack which happened at about 10.20pm.
He and the victim knew each other. The arrested man has been bailed until Monday 8 April while officers make further inquiries.
Detective Constable Aran Boyt, from Brighton and Hove CID, said: “We are appealing for anyone who was in the area and heard or saw any suspicious activity to please get in touch.”
Witnesses or anyone with information is asked to call Sussex Police on 101 or the independent charity Crimestoppers anonymously on 0800 555111.