One person has been treated for botulism and two others have been admitted to hospital with suspected cases which health authorities believe is linked to unregulated cosmetic injections.

NSW Health said in a statement on Saturday said all three cases received anti-wrinkle injections from the same person on the same day at a Sydney home about two weeks ago.

Investigations into the specific anti-wrinkle product that was used are under way.

NSW Health is working with the Health Care Complaints Commission and NSW Police on this matter.

Botulism is a rare but serious condition caused by a toxin that attacks the body’s nerves, with a range of symptoms including progressive weakness, difficulty swallowing, drooping eyelids, blurred or double vision and difficulty breathing.

NSW Health executive director of health protection Dr Jeremy McAnulty said the case was a reminder of the potential side effects of unregulated cosmetic injections.

“Cosmetic injections, if used incorrectly, could result in serious harm and even death in the most serious of cases,” Dr McAnulty said.

“Botulism, although rare, can be fatal, which is why it is so important that anyone receiving cosmetic injections does so under the supervision of an appropriately registered health practitioner.

“In this particular case, investigations are continuing, but we want people to be aware of the symptoms of botulism as others could have been exposed.”

Botulinum toxin, or botox for short, is often used as an anti-wrinkle agent.

One of the most potent toxins knowns known to science, botox is commonly used for medical and cosmetic purposes.