Banned in some countries, promoted in others - the drug hydroxychloroquine as a potential treatment for the new coronavirus is dividing opinion worldwide.
Scientists looking to find licenced medicines that could be repurposed as a treatment for Covid-19 had started tests of hydroxychloroquine, normally used to treat arthritis, and chloroquine, an anti-malarial.
Both drugs can produce potentially serious side effects, particularly heart arrhythmia, leading many experts to warn against their use outside of clinical trials.
But that has not stopped prominent figures like US President Donald Trump endorsing hydroxychloroquine despite a lack of evidence of its efficacy.