POLICE have made a renewed appeal to track down three people they believe could have seen incidents leading to the death of Robert Hart at the Parklife Weekender.

Robert, aged 26, died on June 11, five days after being assaulted and suffering a bleed to the brain at the festival held in Heaton Park.

Detectives say they have managed to track down one witness, but are asking for help in finding three witnesses who they believe could hold the key to tracking down Robert’s killer.

The organisers of the festival have offered a £20,000 reward for information leading to the conviction of his killer, and Crimestoppers added a £3,000 reward during an episode of Crimewatch last month.

Police originally issued images of nine witnesses who were stood near Robert at the event, nine of which have now been found, but are asking for people to help them in finding the other three.

Last week, Robert’s girlfriend Gemma Parry appealed to the public for help in tracing the witnesses.

She said: "Despite the best efforts of Greater Manchester Police officers, Rob's family and myself to persuade him to do so, it is becoming less and less likely that the man responsible for his death is going to come forward of his own accord.

"That makes these potential witnesses all the more important, as they may well hold the key for police to track down the man who took Rob away from me, from his mother, brother, sisters, nieces and nephews.”

Robert’s attacker is described as a mixed race male, aged in his late 20's and around 6ft 1.

He has a muscular build and short, dark hair which was shaved at the sides. He was also wearing shorts and a blue, bomber-style jacket with the letter 'A' in white on the front.

Anyone with information can call the police incident room on 0161 856 9283 or email mit.syndicate8@gmp.police.uk.