A strange object has washed up on a beach in New Zealand, sparking a social media debate about what it could be.

The large object covered in barnacles was spotted on Muriwai Beach in Auckland by local resident Melissa Doubleday.

She posted the photo on the Muriwai & Waimauku Area Community Group, asking: “Just curious to know if anyone knows what this is??! Washed up on Muriwai Beach.”