The newspaper said that it had seen a copy of the results from the WHO's Solidarity trial that studied the effects of using remdesivir and three other drugs to treat COVID-19.

The results appeared to show that all four drugs had little effect in reducing patient mortality, the newspaper cited the WHO as saying.

"These remdesivir, hydroxychloroquine, lopinavir and interferon regimens appeared to have little effect on in-hospital mortality," the study said, as quoted by the newspaper.

The study, which the WHO admitted has yet to be subject to peer review, also found that the four treatments had little effect on reducing the time patients were required to spend in hospital.

Remdesivir, which is produced by US pharmaceutical firm Gilead Sciences under the brand name Veklury, was initially developed to treat Ebola and has received partial approval for use in treating COVID-19 patients in the United States and the European Union.

Following US President Donald Trump's positive test for COVID-19, medical professionals said that he would undergo a five-day course of remdesivir. Since then, the president has said that he has achieved immunity from the disease and is in good health.