The 31 year old suspect has been taken to Antrim police station for questioning.
Two men arrested yesterday, aged 22 and 46, remain in custody.
Detective Chief Inspector Michael Harvey said: “I am extending the scope of our appeal for information to include the railway station in Ballymoney which is in the same general area as the house at Riverview Park where Brian was attacked.
“I want to hear from anyone who was in the station, close to the station or on a train passing through the station between 10.20pm and 10.30pm last Monday night.
“They may have seen a number of men in this vicinity and they may be able to assist the investigation.
“Anyone with any information can contact detectives at the special incident room at Ballymoney police station on the non-emergency number 101.
“Or they can provide information anonymously to the independent charity Crimestoppers on 0800 555 111.”