The US Vice-President, Dick Cheney, and Senator Barack Obama are related through a distant Huguenot ancestor who moved to the US from France in the 17th century.
Mr Obama, the only African-American member of the US Senate, now running second in the race for the Democratic nomination for the 2008 presidential election, is also distantly related to President George Bush.
In fact they are 11th cousins, sharing ancestors – Samuel Hinckley and Sarah Soole Hinckley – from 17th-century Massachusetts.
The Chicago Sun Times first uncovered the supposed links between the Obama clan and President Bush and Mr Cheney last month. According to the newspaper report, Mr Obama is related to Mr Cheney through Mareen Duvall. The link makes them ninth cousins once removed.
However, Lynne Cheney, the Vice-President's wife, says that her research indicates that they are actually eighth cousins. She told MSNBC that she discovered the link, traced back to a Huguenot who figured prominently in Maryland history, while researching a book.
"This is such an amazing story," Mrs Cheney told the network, "that one ancestor, a man that came to Maryland, could be responsible down the family line for lives that have taken such different and varied paths as Dick's and Barack Obama's."
Mrs Cheney's researcher at the conservative American Enterprise Institute said the Vice-President's wife discovered an early Cheney settler named Richard Cheney, whose granddaughter married Samuel Duvall, the son of Mareen and Susannah Duvall.
When Mrs Cheney read a story about how Mr Obama was related to Mareen, she realised the link.
The Chicago Sun Times story also showed a link between Mr Obama and the former US president Harry Truman, also through Mareen Duvall.
Mr Obama, whose mother was white, has not commented on the discovery. But his campaign made light of the link, without confirming it. "Obviously, Dick Cheney is the black sheep of the family," Mr Barack's spokesman, Bill Burton, said.