A new study has found that higher numbers of people are taking interest in untried and possibly dangerous therapies to treat the novel coronavirus after they were recommended by high-profile US public figures.

In the United States, researchers for JAMA Internal Medicine, a medical journal, noted an enormous increase in the number of Google searches for two malaria drugs after they were recommended as possible virus remedies, first by Tesla founder Elon Musk and then by US President Donald Trump.

Searches by people looking where they could buy chloroquine increased by 442%, while queries about hydroxychloroquine rose by 1,389%, said the team led by Michael Liu of Oxford University in Britain.

Interest among Google users in both substances remained higher than average even after the death of a man by chloroquine poisoning was reported.

"Endorsements can lead to unsupervised use of the products with dangerous consequences to the people who take them, and hoarding of these medications can result in shortages for those who require them for legitimate health reasons," the authors said.

"In times of public health crises, demand for unproven and potentially hazardous Covid-19 treatments is massively increased by endorsements," they wrote, adding, "Public health leaders, regulatory agencies, media, and retailers must amplify accurate information."

The World Health Organisation has warned people against trying to treat the virus with substances whose effectiveness has yet to be proved.

A study released recently from the United States showed that patients suffering from the respiratory disease Covid-19 who took hydroxychloroquine had a higher death rate than a control group.

 - dpa