Apricot stones sold for health benefits could be fatal in high doses, the food safety watchdog has warned.
Some claim apricot seeds can cure cancer
Apricot kernels are thought to contain high levels of vitamin B17, which is described as an immune system booster and even sold as a cancer treatment.
But the Food Standards Agency said they also produce cyanide and can be poisonous in high doses.
It is now recommending that people consume no more than two bitter apricot kernels in a single day.
An FSA spokesman said there were reports from overseas of "very serious health effects" being associated with the consumption of 20 to 30 kernels in a short period of time.
He added: "They could be potentially lethal in high enough doses."
Natural food retailer Julian Graves was selling packs with a recommended daily dose of 10 kernels and has since pulled them from its shelves.
It said it had begun selling the apricot kernels due to customer demand and would do so again with a revised recommended dosage if the food watchdog gave it permission.
The seeds however are also available through specialist websites.
Cancer Research UK says of vitamin B17: "According to claims made on the Internet, this substance found in apricot pips is a highly active compound that can cure cancer.
"Unfortunately this is simply not true. The whole reason for the existence of Cancer Research UK is to find cures for cancers.
"If simply eating apricot seeds could cure cancer, no one would be more delighted than us."