US President Donald Trump has said the malaria medication was only rejected as a Covid-19 treatment because he had recommended its use. Photo: BBC

He said the malaria medication was only rejected as a Covid-19 treatment because he had recommended its use.

His remarks come after Twitter banned his eldest son for posting a clip promoting hydroxychloroquine.

There is no evidence the drug can fight the virus, and regulators warn it may cause heart problems.

On Wednesday Dr Anthony Fauci, a leading member of the White House coronavirus task force, told the BBC that hydroxychloroquine was not effective against the virus.

"We know that every single good study - and by good study I mean randomised control study in which the data are firm and believable - has shown that hydroxychloroquine is not effective in the treatment of Covid-19," he said.

Last month, the US Food and Drug Administration (FDA) cautioned against using the drug to treat coronavirus patients, following reports of "serious heart rhythm problems" and other health issues.

The FDA also revoked its emergency-use authorisation for the drug to treat Covid-19. The World Health Organization (WHO) says "there is currently no proof" that it is effective as a treatment or prevents Covid-19.