At least eight people have wound up in hospital suffering poisoning symptoms after consuming large amounts of poppy seeds, NSW Health warns.
Cases have also been reported in other states.
"High levels of a naturally occurring chemical in the raw poppy seeds may be a factor," NSW Health warned on Friday.
People have been purposefully consuming the large quantities in a liquid form, leading to seizures, severe muscle pain, spasms, cramping and stiffness.
"We are urging anyone who has had large quantities of poppy seeds, for example as a drink, and who experiences any unusual and severe symptoms to seek immediate medical attention by visiting their nearest emergency department," NSW Poisons Information Centre medical director Darren Roberts said.
A highly-regulated but valuable crop, particularly in Tasmania, poppies are used by multinational pharmaceutical companies, turning them into powerful prescription painkillers, while illegal producers rely on poppies to make heroin.
Poppy seeds are also a common and easily obtainable ingredient in cakes and breads, the "naturally occurring chemical" within destroyed during the baking process.
Those have not driven any poisoning cases, NSW Health says.
