As I understand it there is research going on because it appears that ethnicity is inherently a factor although I don't think we know why yet
I'm pretty sure that has NOT been claimed.
Here's the official study
www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/deaths/articles/coronavirusrelateddeathsbyethnicgroupenglandandwales/2march2020to10april2020
And supporting data
www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/deaths/methodologies/coronavirusrelateddeathsbyethnicgroupenglandandwalesmethodology
We know that black people are more likely to have died from covid-19.
We don't know why, however it's blindingly obvious that for example some jobs have had a zero occupational risk for a long time, e.g., people working from home in desk jobs, while others have had a continued high occupational risk , e.g. meat processing, where people are in confined spaces which are ideal for viral spread.
Essentially if you work in a factory you are CERTAIN to have been exposed to viral load, whereas people sitting at home doing legal work etc will not.
We know for absolute fact that there are huge disparities in the jobs that different ethnicities do, but also that in general the lowest paid jobs are manual labour, which cannot be done from home.
Thats on top of the extra risk for example in the fact that 25% of the entire Bangladeshi population of the UK lives in one London borough, and London experienced the first and highest infection rate.
It might be that there are inherent racial differences but these aren't as obvious as the fact that say taxi drivers are going to be exposed to far more infected people than computer programmers, of whatever race.