A post mortem is due to be carried out today into the death of Paul McCauley at the weekend.
The 38-year-old passed away on Saturday morning at a care unit in Derry surrounded by his loving family.
The father-of-one was attacked by a 15-strong loyalist mob while attending a barbecue in the Waterside area of the city in July 2006.
The Catholic civil servant sustained a merciless beating before the gang then jumped on his fractured skull.
Paul was left in a vegetative state following the sectarian attack and never regained consciousness.
A pathologist will today examine his remains to give murder squad detectives from the PSNI’s Major Investigation Team an exact cause of his death.
This has heaped more anguish and heartache on his parents Jim and Cathy who have never been away from his side since Paul was hospitalised.
Jim McCauley believes the UDA was involved in the attack on his son.
Said heartbroken dad Jim: “Because the police have turned the investigation into a murder inquiry, there will be a post-mortem on Paul’s body, which has added to our stress, something Cathy, Paul’s mother is finding particularly difficult.
“We have never been separated for as much as a day from Paul since the attack.
“Every single day we spent with him, but now he will be with the coroner in Belfast until later this week and that is hard for us to accept.
“Police have to go through nine years of medical records to filter out what will be relevant to their investigation, so we are not sure yet when our son will be given back to us.”
Only one man – Daryl Proctor – was jailed for the violent assault at Chapel Road in the city, while 25 others were arrested and questioned.
Proctor was released from prison this year.
The other members of the gang remain at large despite repeated police appeals for information.
The detective now leading the murder hunt, Chief Inspector Michael Harvey, said: “In memory of Paul, for the McCauley family and in the interests of justice, police stand ready to explore any opportunities provided either by a change in circumstances or a qualm of conscience.
“The investigation remains open and detectives are committed to bringing those responsible to justice.
“Paul was an innocent victim of an unprovoked sectarian assault.
“Our Chief Constable (George Hamilton) said last year he was sorry that more people had not been brought to justice than the one individual who was convicted and sentenced.”
He added: “On behalf of the entire police family, I want to extend our deepest sympathies to the McCauley family following Paul’s death.
“They have conducted themselves with great dignity over the past almost nine years since the vicious attack on Paul and his friends.
“The love and care they gave to Paul have been a beacon of light in a tragically dark set of circumstances.
“They have been a compelling voice on Paul’s behalf, a voice with dignity, energy and compassion.”
Anyone with information that can help police catch Paul’s killers is asked to ring detectives in Derry on the 101 non-emergency number.
Or alternatively information can be passed anonymously through Crimestoppers on freephone 0800 555 111.