When two teenagers found a woman's body beside a creek off a walking track in Hornsby bushland, NSW police called in the homicide squad.

But now the main suspects are poverty and winter.

The woman's body was found beside a creek in the Berowra Valley Regional Park. Credit:Peter Rae

"Preliminary post-mortem findings suggest the woman's death is not suspicious," a police spokesman said on Wednesday.

"She may have died of hypothermia. It is believed she was sleeping rough."