A murder investigation has been launched after the death of a father-of-two 15 years after he was brutally attacked in West London.
A group of at least eight men assaulted Rajesh Verma near the entrance of Acton Park on 31 August, 2003, including one who used garden shears to stab him in the head.
As a result of the attack, then 42-year-old Mr Verma suffered severe brain damage.
A full police investigation was carried out in 2003, but no suspects were ever arrested or charged.
Mr Verma was treated in hospital before being discharged. But he was left with a number of health issues due to the damage to his brain.
In 2015, he had a major heart attack, which resulted in a lack of oxygen to his brain that further complicated the existing damage.
This left him unresponsive and unable to move or speak for the last 18 months of his life.
Mr Verma also suffered from epilepsy as a result of the attack and broke his hip in 2017 during a fitting episode.
He died on 27 May 2018.
His wife, Roma, said their children were 11 and 13 when their lives were turned upside down by the attack.
She said: "We chose to care for him at home in the way that he had cared for all of us.
"Each member of the family helped to care for him. He was unable to think, move, talk or walk, but we still felt he could feel our presence and perservered.
"He required 24-hour assistance and we gave it. We watched him in the same position day after day. Life was all about him, but we all had hope."
Mrs Verma added that the "random and unexpected attack" had left a "huge gap" in their hearts.
A special post-mortem took place in June 2018 and a pathologist concluded there was a causal link between the 2003 attack and his death.
A verdict of unlawful killing was recorded at an inquest held at West London Coroners Court on 28 November last year.
The case has now been classified as a murder investigation.
A £20,000 reward is being offered for any information that leads to the arrest and conviction of Mr Verma's killer.
Lead investigator, Detective Chief Inspector Noel McHugh, said the attack involved "ferocious violence by a group of men" one of whom "stabbed him in the head with a set of garden shears found near the crime scene".
He said: "We believe Rajesh was attacked after he intervened in a dispute between one of his friends and another individual."
The suspects are believed to be local to the Acton area and are likely to still be living there or have links to the area, he added.
They are described as all being of East African appearance.
"Rajesh's family have not had any justice for 17 years and we are committed to solving this murder," Det Chief Insp McHugh said.
Anyone with information should call 020 8785 8099 or Crimestoppers on 0800 555 111.