Police were called shortly after 3am on Sunday 23 June 2019 to a report of concern for the welfare of a boy at Thomasson Park, Bolton.
A GMP spokesman said: “Emergency services attended but the boy, believed to be aged 17, was sadly pronounced dead at the scene.
“A scene remains in place in Thomasson Park.
“Officers are keeping an open mind as to the circumstances surrounding the death, but it is not currently being treated as suspicious.”
Anyone with information should GMP on 0161 856 5757 or the independent charity Crimestoppers, anonymously, on 0800 555 111.