Prime Minister Boris Johnson's senior adviser on ethnic minorities has quit, it has been announced.
Samuel Kasumu will leave his post as special adviser for civil society and communities in May.
The news comes a day after a government-backed review of racial disparities in Britain was published. However, Downing Street sources have rejected suggestions that his departure was linked to the findings of the review.
According to Politico, he told colleagues of his decision on Tuesday morning, just as the findings of the report were released.
The BBC also reported that he had drafted and retracted a resignation letter in February, in which he accused the Conservatives of pursuing "a politics steeped in division" and suggested Kemi Badenoch, the equalities minister, may have been in breach of the ministerial code over her row with a HuffPost journalist, where she criticised them for asking her why she had not appeared in a social media video featuring black MPs encouraging take-up of vaccines.
Mr Kasumu criticised the government's response to Ms Badenoch's actions, saying: "It was not OK or justifiable, but somehow nothing was said. I waited, and waited, for something from the senior leadership team to even point to an expected standard, but it did not materialise."
The Commission on Race and Ethnic Disparities - set up last year after Black Lives Matter protests - claimed the UK "no longer" had a system rigged against minorities.
The report argued there is an "increasingly strident form of anti-racism thinking that seeks to explain all minority disadvantage through the prism of white discrimination", which diverts attention away from other factors behind disparities of outcome.
But racial equality campaigners have criticised the findings and Labour accused the government of downplaying institutional racism.
Labour's shadow women and equalities secretary Marsha de Cordova said: "To have your most senior advisor on ethnic minorities quit as you publish a so-called landmark report on race in the UK is telling of how far removed the Tories are from the everyday lived experiences of Black, Asian and ethnic minority people.
"Their divisive report appears to glorify slavery and suggests that institutional racism does not exist despite the evidence to the contrary. It is no wonder they are losing the expertise from their team."