A white baby born to a black couple will undergo genetic tests as the parents try to discover if they have any white ancestry.

Nmachi Ihegboro was born in the UK on Sunday with a full head of blonde-hair and white skin, despite having no known Caucasian ancestry from her black, Nigerian-born parents, The Sun reported.

The devout Christian couple were astonished to discover they had given birth to a white baby, describing her as a “miracle”.

So how can a white baby born to a black couple be explained?

Geneticist Dr Mark Thomas, of University College, London, said the odds of the baby’s white colouring were “between many millions to one and a million to one”.

He said: “I suspect there’s been a mixture of a mutation, like albinism, combined with a dormant white gene.”

Professor Bryan Sykes, head of Human Genetics at Oxford University and Britain’s leading expert, said:

“In mixed race humans, the lighter variant of skin tone may come out in a child – and this can sometimes be startlingly different to the skin of the parents. This might be the case where there is a lot of genetic mixing, as in Afro-Caribbean populations. But in Nigeria there is little mixing.”

“The hair is extremely unusual. Even many blonde children don’t have blonde hair like this at birth.”

The baby’s parents have agreed to let experts study Nmachi.