Auckland Council has banned 'mermaid tail' toys from their leisure centres in response to fears they could be dangerous for users, especially children.
The popular swimming toy straps the wearer's legs together into either a single fin or a tail, designed to make the user swim like a mermaid.
But mermaid tails have faced a wave of criticism worldwide, amplified in the lead-up to Christmas.
By binding the legs together, the pool toys can pose a serious danger to weak swimmers and children.
The New Zealand Recreation Association says the fish tails were one of the most coveted gifts of Christmas but is deemed unsafe to use in public pools, and a distraction to lifeguards.
The announcement of Auckland Council's ban was posted on Stanmore Bay Pool and Leisure Centre's Facebook page.
"We wish to advise our customers that ALL mermaid tails and fins are no longer permitted in any Auckland Council Leisure facility," the post reads.
They decided to implement the ban because the toys hinder the ability for children to move their legs while swimming, they say, and because it promotes prolonged underwater swimming, which can lead to blackouts in shallow water.
"Mermaid tails are definitely causing concerns both here and in Australia, and have already been banned from public pool use in the UK," Auckland Council leisure manager Rob McGee said today.
"While they are designed for competent swimmers to use in the water, even the manufacturers recommend one-to-one supervision, which we can't give in public pools."
Mr McGee says the tails distract lifeguards from their main role.
"So far most pools have only seen one or two mermaids, but given oversees experiences, the focus on isolated swimmers puts other pool users at risk, so we are asking parents to keep the mermaid tails for home pools where they can have the direct one-on-one level of parental supervision."
A video from the US posted on YouTube mid-last year highlights how quickly things can go wrong using the toy.
In the video, a young girl wearing a mermaid tail attempts to do an underwater flip in an above-ground pool, only to get into difficulties when she couldn't move her legs. She was quickly rescued by her mother, who was supervising close-by.
YMCA in Australia's Victoria state banned the swimming toy at more than 50 pools through the state earlier this year, while public pools in Canada's city of Edmonton banned the toys last year.