WASHINGTON - U.S. First Lady Michelle Obama’s great-great-great grandfather was white.

According to The Sun, Obama’s great-great-great grandmother Melvinia Shields, a slave, had a son in 1859 and the father is believed to be the white son-in-law of her owner.

Historians said Melvinia, who was 15 at the time of the birth, could have been raped on the plantation where she worked in South Carolina.

Her son was Dolphus Shields, Michelle’s great-great grandfather, stood out at the time because of his light skin.

Mrs Obama, whose husband Barack had a black Kenyan father and a white American mother, refused to comment.

According to The Times, clues to the most enduring mystery of Obama family history emerged in an investigation conducted recently.

The breakthrough in piecing together a journey across five generations from the slave-holding South to the White House came with the discovery of a will written in 1850 by David Patterson, a South Carolina estate-owner.

The document listed the “negro girl Melvinia” in an inventory of his property, along with nine other slaves and a miscellany of assets including two tablecloths, three pairs of curtains and a coffee mill.

Then just six years old, Melvinia passed to Patterson’s wife, who according to the will was to inherit “the use and service of the said negro girl, her issue and increase, if any”.

The identity of Melvinia Shields and new information about her descendants provides the first concrete evidence for President Obama’s ringing declaration in his one major speech on race during last year’s campaign that he was “married to a black American who carries within her the blood of slaves and slave owners”.

Rather than holding on to the young slave, who died in 1938 without knowing who her parents were, Patterson sent her to live with relatives in Georgia. It was there, according to census records studied by The New York Times, that she gave birth to four children, at least one of them fathered by a white man who may have been the Pattersons’ son-in-law, one of his sons, or a visitor to their farm.

Dolfus Shields seized on the opportunities offered by emancipation and moved to Birmingham, Alabama, where he is still remembered by parishioners as the founder of the First Ebenezer Baptist Church, and for his light skin.

Dolfus Shields is buried in a neglected black cemetery in Birmingham but in life counted whites among his friends and customers at a carpentry workshop in the white section of the city.

His grandson, Purnell Shields, moved to Chicago as part of the Great Migration between the wars.

He married a nurse, Rebecca Jumper. Their daughter, Marian Shields Robinson, is Michelle Obama’s mother and now lives with the First Family in the White House. (ANI)