Coronavirus patients from black African backgrounds in England and Wales are dying at more than triple the rate of white Britons, a study suggests.
The Institute for Fiscal Studies (IFS) said a higher proportion of people from ethnic minority backgrounds live in areas hit harder by Covid-19.
However, they tend to be younger on average, so should be less vulnerable.
But the report found various black, Asian and minority ethnic groups were experiencing higher per capita deaths.
And after accounting for differences in age, sex and geography, the study estimated that the death rate for people of black African heritage was 3.5 times higher than for white Britons.
It added that for people of black Caribbean heritage, per capita deaths were 1.7 times higher, rising to 2.7 times higher for those with Pakistani heritage.
The IFS study said given demographic and geographic profiles, most minority ethnic groups are dying in "excess" numbers in hospitals.
A government review into the issue is currently under way, led by Prof Kevin Fenton, regional director for London at Public Health England.
Ross Warwick, a research economist at IFS, said there was "no single explanation and different factors may be more important for different groups".
"Black Africans are particularly likely to be employed in key worker roles which might put them at risk," he said, "while older Bangladeshis appear vulnerable on the basis of underlying health conditions."
Two-thirds of Bangladeshi men over the age of 60 have a long-term health condition that would put them at risk from infection.
More than 20% of black African women are employed in health and social care roles while Pakistani men are 90% more likely to work in healthcare roles than their white British counterparts.
Similarly, while Indian people make up just 3% of the working population in England and Wales, they account for 14% of doctors, according to the research.
Prof Tim Cook, honorary professor in anaesthesia at the University of Bristol, said the high number of ethnic minority healthcare workers dying from Covid-19 was "striking".
BBC News analysis of 135 healthcare workers whose deaths have been publicly announced found 84 were from ethnic minority backgrounds.
Within this, 29 are reportedly from black communities; 26 from South Asian backgrounds; 23 from East Asian backgrounds, of which 17 are Filipino; and four from Arabic backgrounds.
In a letter to local trusts and GPs sent this week, the head of NHS England advised staff from black, Asian and ethnic minority groups should be "risk-assessed" as a precaution based on the growing data.
Prof Lucinda Platt, from the London School of Economics, said there were also noticeable differences in economic vulnerability between ethnic groups as a result of the lockdown.
"Bangladeshi men are four times as likely as white British men to have jobs in shutdown industries, with Pakistani men nearly three times as likely," she said.
This is partly because of their heavy concentration in the restaurant and taxi sector, she suggested.
"Household savings are lower than average among black Africans, black Caribbeans and Bangladeshis," she added.
"By contrast, Indians and the largely foreign-born other white group do not seem to be facing disproportionate economic risks."