An unidentified item has been taken away by the New Zealand Defence Force's Explosive Ordnance Disposal team after a callout on Tuesday night.
Police attended a callout to the Newton Road Overbridge in Eden Terrace, a suburb of Auckland, following reports of an item of concern.
Police CIB staff would make inquiries to identify the small object and ascertain why it was left on the overbridge, a police spokesman said.
Jonathan Sweeney said he rode past the item in question while on his bike at 5.50pm.
"It appeared to be a car battery on fire.
"It was spitting out sparks as I rode past and people were keeping their distance."
Police along with the Fire Service attended the call out.
Police have now left the scene.