The police in Whanganui say they are not treating the death of a 26-year-old man as suspicious.
Tyrone Box was found dead by members of the public at Te Mana Park in Whanganui on Monday evening.
Police launched an investigation but said a post mortem today found no evidence of injury or trauma.
Further medical tests were underway to determine how Mr Box died and the death had been referred to the Coroner.
Radio New Zealand records show Mr Box was one of 13 people charged over a drive-by shooting in the city in 2007.
Two year old Jhia Te Tua was fatally shot while asleep in her home.
Most of the defendants had gang links.
Tyrone Box pleaded guilty to manslaughter and was jailed for seven years.
The case led to a crackdown on the wearing of gang patches in Whanganui, driven by the then Mayor Michael Laws.