Three of the authors of a study which found that taking an anti-malaria drug could increase the risk of mortality in COVID-19 patients retracted their paper on Thursday.
The study, released on May 22 in The Lancet medical journal, led to several clinical trials into the use of hydroxychloroquine to treat COVID-19 being halted.
The Lancet said in a statement that the authors were "unable to complete an independent audit of the data underpinning their analysis" which had been provided by Surgisphere, a healthcare analytics company based in the US.
"As a result, they have concluded that they "can no longer vouch for the veracity of the primary data sources"," The Lancet statement added.
The observational analysis looked at nearly 100,000 COVID-19 patients worldwide, including nearly 15,000 who were treated with hydroxychloroquine or chloroquine.
It concluded that there were no benefits to taking the drugs for COVID-19 patients and that there was instead a greater risk of heart problems.
Hydroxychloroquine has been much hyped as a COVID-19 treatment since French doctor Didier Raoult said he was treating patients in Marseille with the drug and an antibiotic. A study he published was however dismissed as too small.
But health authorities worldwide, including the World Health Organisation (WHO) launched their own clinical trials to determine the drug's efficiency to combat the novel coronavirus, stressing however that patients should not self-administer the drug because of the risk of serious side effects.
Many of the trials were halted after the release of the study, including in France.
The WHO's Solidarity Trial Executive Group, which implemented a temporary pause of its trial because of concerns over the drug's safety, announced on Wednesday that it had "endorsed the continuation of all arms of the Trial, including the use of hydroxychloroquine".