Barack Obama's mother 'probably the descendant of a black slave'

President Barack Obama's white mother was probably the descendant of a black slave, genealogists have concluded after two years of research and DNA testing.

Barack Obama's father, also named Barack Obama, and mother, Stanley Ann Dunham

Mr Obama was always assumed to have had no ancestors who arrived in the US through slavery, placing the first black president at odds with most African-Americans across the country.

His father, Barack senior, travelled from Kenya to study in Hawaii, where his son was born in 1961 – prompting some commentators to claim Mr Obama did not fully share the experience of many black voters.

However, researchers now believe that they have traced back the family tree of the President's mother, Stanley Ann Dunham, by almost four centuries to an African servant in Virginia called John Punch.

The finding would mean that Mr Obama is in fact the 11th great-grandson of the first documented slave in American history, who was punished for trying to escape in 1640 by being indentured for life.

"Two of the most historically significant African-Americans in the history of our country are, amazingly, directly related," said Joseph Shumway, one of the leading genealogists on the project.

Records state that Mr Punch had children with a white woman, who passed her "free" status on to their offspring. They went on to be successful landowners in Virginia, where slavery was later widespread.

DNA tests carried out by the researchers for ancestry.com, suggest that Mr Punch's mixed-race descendants altered their name to Bunch, a family known to be among Ms Dunham's forebears.

While the destruction of some records means there is no absolute proof, the researchers said DNA evidence and records of another branch of the Bunch family being "mulatto" left them confident.

Elizabeth Shown Mills, a past president of the Board for Certification of Genealogists, who carried out an independent review of the study, said the "evidence of African origin is indisputable" in the Bunch line. "The surviving paper trail points solely to John Punch as the logical candidate," she added.

Jamal Simmons, a political analyst specialising in race who worked for Bill Clinton, the former president, said the findings showed accusations Mr Obama was somehow "not black enough" to be practically meaningless.

"This is more evidence of how intertwined the lives and histories of Americans really are," Mr Simmons told The Daily Telegraph. "We really have become that mixing bowl of cultures. That used not to be so accepted, but the negative connotations are fading as more people discover their roots."