The Office for National Statistics said it recorded 13,121 deaths by April 10 in England and Wales, which account for the vast majority of Britain's population, compared with 9,288 in the government's daily toll for those who died in hospital.

The latest hospital deaths data published on Monday show 16,509 people had died across the United Kingdom.

If the United Kingdom's figures are underestimating the death toll by a similar figure, then the true death toll for the country as a whole could be above 23,000 based on the latest data - making it the second worst hit in Europe after Italy.

However, the gap between the daily figures published by the government and the later, more comprehensive ONS data, has narrowed with each week that passes, and may have gone further reduced by the time the ONS reports on the latest toll.

COVID-19, the respiratory disease caused by the novel coronavirus, was mentioned in a third of all death certificates issued in England and Wales in the week to April 19.

In London, more than half of the death certificates issued that week mentioned COVID-19.

The ONS figures includes deaths in care homes and hospices and are based on mentions of COVID-19 on death certificates, whether or not the deceased had tested positive for coronavirus.

"In care homes settings there are now double the number of deaths from all causes, all mortality causes, double the number in care homes than there were two weeks previously," ONS statistician Nick Stripe told the BBC.

"About 17% of those deaths mention COVID on the death certificate."