Two men, aged 28 and 36, were arrested in Derry and Coleraine this morning on suspicion of murder and attempted murder.
A 27 year old woman was arrested last night in Derry on suspicion of withholding information.
They have all been taken to Strand Road police station for questioning.
38-year-old Paul died last month in a care facility almost nine years after an attack in July 2006.
He was attending a summer BBQ at the rear of a house in Chapel Road on 15 July 2006.
At 3.20am on 16 July, only three people remained at the BBQ.
A group of up to 15 people came from out of the bushes and attacked Paul and two of his friends.
After the assault the group made off in the direction of Irish Street.
Last Saturday 24-year-old Piper John McClement (formerly known as Daryll Procter) appeared at Derry Magistrate’s Court charged with the murder of Paul McCauley.