US First Lady Michelle Obama's ancestry can be traced to a slave owner from what is now Northern Ireland, who emigrated to America in the 1700s.
A new book claims that Andrew Shields, who fought against the British in the American War of Independence, was Mrs Obama's great-great-great-great-great-great-grandfather and his family were slave owners.
Her great-great-great-grandmother Melvinia was a slave who had children by Charles Shields, grandson of Andrew Shields. One of those children, Dolphus Shields, born in 1859, was Michelle Obama's direct ancestor.
The claims are made in American Tapestry: The Story of the Black, White and Multiracial Ancestors of Michelle Obama by Rachel L Swarns, a writer with the New York Times.
DNA technology was used to prove the link, and among the genealogists who helped trace Mrs Obama's roots was Megan Smolenyak, who discovered that President Obama's roots went back to Moneygall in Co Offaly.
While the book does not identify where the Shields came from, it was most likely Ulster as the family was Protestant and there was considerable Scots-Irish emigration to the American South at the time.
It traces dozens of white relatives of Michelle Obama, none of whom knew of their connection through slavery to the first lady. Most were shocked to learn the connection and hoped that the Shields-Melvinia relationship was not one of rape, but love.
“You really don't like to face this kind of thing,” said Joan Tribble, whose ancestors owned the first lady's relative.
“To me, it's an obvious love story,” another descendant, Aliene Shields, added, pointing out they had several children together.
Ms Smolenyak began the project just before Mr Obama was elected president and she said she hoped her discovery would please the first lady.