New Zealand Food Safety advises people not to consume a seaweed tonic sold in a glass bottle labelled 'NZ Focuidan' or an unlabelled bottle.
"The tonic presents a concerning food safety risk because it has not been through the required checks and balances to make sure it is safe to consume," said New Zealand Food Safety’s deputy director-general, Vincent Arbuckle.
Arbuckle continued that the product has not been registered under the Food Act, which means consumers cannot be certain that risks have been properly identified and managed.
"Seaweed can contain chemical hazards such as inorganic arsenic, lead, cadmium, and mercury.”
NZ Focuidan is made with seaweed, which can be high in iodine. Without proper controls, treatments and dosage information, iodine can be dangerous, particularly to those with thyroid conditions.
The product also makes prohibited therapeutic claims, and consumers are advised not to be led by these claims.
"If you have bought this product, which is either labelled 'NZ Focuidan' or has limited or no identifying labelling or branding, do not consume it and throw it out."
Available evidence suggests the seaweed tonic has been available for sale through informal sellers and local markets.
New Zealand Food Safety is working to ensure this product is removed from sale.
There have been no reports of associated illness to date.
If individuals have consumed this product and have health concerns, they are encouraged to seek medical advice.