A search is under way on Great Barrier Island after a bike was left at the start of a track.
Police are appealing for help to identify the owner of of the bike, believed to have been at the start of Palmers Track since Monday.
Department of Conservation staff have been visiting huts and speaking to trampers and police on Great Barrier Island. They have been making inquiries but have not located the owner.
Police are increasingly concerned that a person may have got into trouble and today began a search and rescue operation, Auckland City Police Inspector Beth Houliston said.
We are really keen to urgently locate the bike owner to ensure they are safe and well, Inspector Houliston said.