Police in Nelson are unsure what to make of a survival blanket discovered in a remote area of the Nelson Lakes National Park.
A hunter in the East Sabine valley found a silver foil blanket spread out in an open area and held down by rocks.
Tramping socks and a food wrapper were also found.
Sherp Tucker of Search and Rescue says the blanket may have been there for a year or two and was obviously meant to draw attention.
The only person missing in the park is American tramper Ed Reynolds, but his last confirmed sighting - in 2009 - was 10 to 15 hours walk away.
Mr Tucker says information from the public could help clear up the mystery.
