A possible attack pictured below is the latest to be investigated by officers following the two-day music festival at Manchester's Heaton Park that attracted more than 140,000 people.
Detectives from Greater Manchester say they are already investigating three serious assaults at the weekend event.
In total, police made 29 arrests plus a further 26 crime reports were submitted, the majority of which were for either assaults or public order offences.
Meanwhile, officers have confirmed that a man punched unconscious by an unknown man has since died.
Robert Hart was dancing with his girlfriend on Saturday night in front of the main stage when he was punched unconscious by an unknown man.