A search and rescue operation is underway on Great Barrier Island, after an unclaimed bike was seen parked near a tramping track for four days

Police are appealing to the public for any information as to who owns the bike after it was spotted there on Monday.

Authorities have released a photo of the black and yellow bicycle leaning up against a large rock near the start of a local tramping track.

An aqua-blue helmet has been carefully placed on the seat.

The Department of Conservation staff have been visiting huts and speaking to trampers in the area to try and find the owner.