A third man has been arrested by Detectives investigating the murder of Paul McCauley in Londonderry in 2006.
A PSNI spokesman said a 61-year-old man was arrested in England and detained in Kent on Wednesday.
He was brought to Musgrave police station in Belfast for questioning.
Yesterday two men - aged 27-years and 28-years - were detained by police in Londonderry and remain in custody.
Mr McCauley died in June 2015 in a care facility, almost nine years after he was attacked at a barbeque.
He was attending a summer BBQ at the rear of a house in Chapel Road on 15 July that year.
At 3.20am on 16 July, only three people remained at the BBQ.
A number of people came out from the bushes and attacked Paul and two of his friends. After the assault the group made off in the direction of Irish Street.
The officer leading the investigation, Detective Chief Inspector Michael Harvey, said: “We said after Paul died that this investigation would take on a renewed momentum and this momentum is continuing. One person has been charged with murder and another individual has been reported to the public prosecution service. Detectives are available to speak with anyone who decides they want to talk to us. Even after almost 10 years, it is not too late to do the right thing and come forward. Anyone with information about the attack and its tragic outcome can speak to detectives on the non-emergency number 101.”