The 51-year-old man was detained by North Yorkshire Police officers after a body was discovered in a flat in Scarborough.
The body of a 48-year-old man was found in the ground floor flat in the Eastborough district of the town on Thursday night.
The victim had been subjected to a violent attack in which he suffered extensive head injuries, according to a North Yorkshire Police spokesman.
House-to-house inquiries are being carried out by police, and forensic investigators have been searching the flat for evidence throughout the weekend.
The suspect, who was arrested on Friday morning, was continuing to be questioned yesterday. However, the victim has yet to be formally identified.