More than 400 UK care home residents were dying with Covid-19 every day during the peak of the pandemic, according to analysis by the PA news agency.
The findings show there were 11 days in April when more than 400 deaths involving Covid-19 were recorded, with the largest number on 17 April when 490 residents died.
Deaths rose by 500 per cent between 1-17 April and in just one week in April there were more than 3,000 Covid-related care home deaths.
PA found it took 43 days for care home deaths to reach 5,000 but only 12 days for that number to double.
By 28 April, after England became the first UK nation to announce it would be testing all care home staff regardless of symptoms, 9,776 residents had died across the UK.
By the end of July, there had been 17,676 deaths in UK care homes.
Care England chief executive Martin Green said the advice had been "slow to come to fruition", particularly with regard to care home visits.
“Many care homes locked down before national guidance came into force. Unfortunately patients were discharged from hospital without testing and this, compacted with insufficient PPE, created huge challenges for care homes,” he added.
A Department for Health and Social Care spokesman said 60 per cent of care homes in England had no Covid outbreak at all and the proportion of coronavirus deaths in care homes is lower in England than many other European countries.
“We have been doing everything we can to ensure care home residents and staff are protected, including testing all residents and staff, provided 200m items of PPE, ring-fenced £600m to prevent infections in care homes and made a further £3.7bn available to councils to address pressures caused by the pandemic - including in adult social care,” he added.
