People suffering from long COVID are reporting a strong smell of fish, sulphur and a sweet sickly odour, as further symptoms of the virus emerge, Sky News reports.
The unusual side-effect is known as parosmia - meaning a distortion of smell - and may be disproportionately affecting young people and healthcare workers.
Ear, nose and throat (ENT) surgeon Professor Nirmal Kumar called the symptom "very strange and very unique".
Prof Kumar, who is also the president of ENT UK, was among the first medics to identify anosmia - loss of smell - as a coronavirus indicator in March.
He urged Public Health England to add it to the symptom list months before it became official guidance.
He has now noted that among the thousands of patients being treated for long-term anosmia across the UK, some are experiencing parosmia.
Prof Kumar told Sky News that patients experience olfactory hallucinations, meaning "sense of smell is distorted, and mostly unpleasantly, unfortunately".
