Christopher Brahney has been missing since Friday night
Police are searching Manchester's Heaton Park for a 22-year-old man who went missing after Friday's gig by The Stone Roses.
Christopher Brahney, from Timperley, was with friends before he disappeared at around 23:30 BST.
Det Insp Deborah Oakes, of Greater Manchester Police, said: "Christopher's family are very worried about him and are desperate for any information."
She added: "We would urge anyone who may have seen him to contact us."
Mr Brahney, who was among 70,000 of the band's fans at the concert, had left the venue with his friends but returned to the park when he discovered he had lost his mobile phone.
Possible sighting
Friends of Mr Brahney have made an appeal to trace him by forming a group on the social media website Facebook.
His mother Jane Brahney appealed to anyone who might have seen him to contact police.
"Phone up the police with any information. We need our son home," she said.
The search could extend to Middleton, north of the park, as police are checking a possible sighting of him on a bus heading towards that area.
His father Stuart Brahney said: "Anyone in the Middleton area can help because we are going to organise his friends and meet there.
"We have concentrated on Manchester, I think it might be time to move on."
