New government figures show that Covid-19 deaths in care homes in England and Wales have risen over fourfold in a week but providers say the toll is even higher.

By 10 April, more than 1,000 care home residents died from the virus, up from 217 in the previous week.

But research by The Guardian newspaper suggests the numbers, compiled by the Office of National Statistics, do not reflect the true scale of the pandemic’s effect on the care sector.

Figures reported by care home providers show the actual death toll is considerably higher, with five of the largest recording 1,052 deaths from confirmed or suspected Covid-19, with the death toll rising sharply in recent days.

At least 412 people died at homes operated by HC-One and Care UK, a company with 122 homes, recorded 140 deaths, a 65% increase, in four days, while Four Seasons Health Care reported more than 160 deaths in its 190 care homes – a 60% increase in six days.

Niall Dickson, chief executive of the NHS Confederation,said the figures were gave grave cause for concern.

“The sharp rise in care home deaths is deeply alarming – this could be the second front in the battle against Covid-19 and we need to do everything we can to support the care sector with the right PPE, training and support in infection control and adequate funding," he said.

“The social care action plan announced last week was welcome but it is clear more needs to be done.

“And if we are to understand the true scale of the spread of Covid-19, the number of deaths in care homes should be released daily in the same way as they are for hospital deaths.

“The overall spike in deaths is also a real concern – we need to know what is behind it as coronavirus cases do not account for all of the extra deaths.

“It may be that coronavirus cases that are going undetected or it may be that other factors related to the lockdown and outbreak are having an impact, such as people not seeking treatment for other conditions.”