DNA clue to Jefferson ancestry puzzle

DNA tests carried out on two British men have shed light on a mystery surrounding the ancestry of Thomas Jefferson, America's third president.

In the 1990s, DNA was taken from male relatives of Jefferson to see if he fathered a son with one of his slaves.

They found the president had a rare genetic signature found mainly in the Middle East and Africa, calling into question his claim of Welsh ancestry.

But this DNA type has now been found in two Britons with the Jefferson surname.