Parklife Festival death: Woman dragged away Robert Hart's attacker

People who were standing close to where Mr Hart was assaulted are being urged to send their pictures and video footage to police

A woman intervened after a man was knocked unconscious at Manchester's Parklife Festival, police have said.

The woman, who wore a pink top and black jacket, dragged the man away after he attacked Robert Hart in Heaton Park at about 21:15 BST on 7 June.

Mr Hart, 26, of Macclesfield, Cheshire, died in hospital four days later.

An aerial photograph, which shows the area where Mr Hart was assaulted, has been released to urge people to send pictures and video footage to police.

A £20,000 reward is on offer to help catch the man responsible for Mr Hart's death

Mr Hart was attacked before Snoop Dogg was due to go on stage, his girlfriend Gemma Parry said.

Police described the woman as blonde with shoulder-length hair about 5ft 7in tall and approximately 20 to 23 years old.

She was with a man about 6ft 1in who was wearing a dark jacket.

Det Insp Richard Eales said: "Several witnesses have pointed towards the fact that this man was at the festival with other people, notably the girl we have described.

Greater Manchester Police issued an e-fit of a man they want to speak to

"There is a strong chance that the person we are looking for, or the people he was with, could be in the background of those pictures or footage and that may prove invaluable to our investigation. "

A £20,000 reward is being offered by the festival organiser to help catch the man responsible for Mr Hart's death.