A major British trial of hydroxychloroquine has found it has "no benefit" for patients hospitalised with the coronavirus, researchers said Friday, announcing they had stopped tests of the drug. 

"We have concluded that there is no beneficial effect of hydroxychloroquine in patients hospitalised with COVID-19," said a statement from the chief investigators in the Recovery trial, which is run by the University of Oxford and is testing a number of potential treatments for the new coronavirus. 

They added they would stop "with immediate effect" recruiting patients to be given hydroxychloroquine, an old malaria and rheumatoid arthritis drug favoured by US President Donald Trump. 

The randomised clinical trial -- considered the gold standard for clinical investigation -- and has recruited a total of 11,000 patients from patients from 175 hospitals in the UK to test a range of drugs. 

Researchers said 1,542 patients were randomly assigned to hydroxychloroquine and compared with 3,132 patients given standard hospital care alone. 

They found "no significant difference" in mortality after 28 days between the two groups, while there was also no evidence it would shorten the amount of time spent in hospital.

The announcement comes in the same week that the World Health Organization (WHO) restarted its trials of hydroxychloroquine after they were temporarily halted because of a now-retracted study in The Lancet medical journal.