Police say an accelerant was used to start a scrub fire in south Auckland in which the burning body of a man was found.
Emergency services were called to McRobbie Road in Kingseat about 6.30am on Thursday.
A woman told police by phone that she had discovered the body alight in some grass.
Police say the results from a post-mortem confirm the victim was a man aged between 15 - 30, but they have not yet been able to identify him.
They say finding out who he is, is the focus of the investigation, and an open mind is being kept about whether his death was self-inflicted or a homicide.