Thomas Jefferson's descendants have decided that the ancestors of one of his slaves cannot join their family club, despite DNA evidence published in Nature suggesting that he fathered at least one of her children.

The Monticello Association, a group of nearly 800 descendants of Jefferson's daughters, voted on 5 May to keep Sally Hemings's descendants out of their group. This means that Hemings's relatives cannot be buried in the graveyard at Monticello, Jefferson's home in Charlottesville, Virginia.

Their vote is the latest twist in a racially charged controversy that has raged since Jefferson's own day, when it was noted that Sally Hemings's children bore a likeness to the third president. That and other evidence fuelled speculation that the author of the Declaration of Independence fathered six children by Hemings, who was a slave at Monticello. She only became pregnant during times when Jefferson stayed there.

Jefferson's descendants have always disputed this speculation. Jefferson's grandchildren claimed that one of his maternal nephews, Samuel or Peter Carr, fathered Hemings's children. But genetic tests published in November 1998 (see Nature 396, 27–28; 1998) eliminated that possibility. The tests compared the Y chromosomes of men descended from Sally Hemings's son Eston with those from the Jefferson and Carr family lines. Eston's Y chromosome was found to be virtually identical to Jefferson's and dissimilar to the Carr chromosome.

The study caused an outcry because it was published in the midst of then-President Bill Clinton's impeachment process. Clinton's supporters seized on it as proof that previous presidents — even the most celebrated ones — had also engaged in sexual indiscretion.

The findings prompted the Thomas Jefferson Foundation, which owns and operates Monticello, to investigate the Hemings connection. In January 2000, it concluded that the DNA study, combined with other evidence, indicated a “high probability that Thomas Jefferson fathered Eston Hemings, and that he most likely was the father of all six of Sally Hemings's children”.

But Jefferson's descendants remain unswayed, and now say that Thomas's brother Randolph was probably Eston's father. “They have not provided conclusive evidence that Thomas Jefferson had a relationship with Sally Hemings,” says Nathaniel Abeles, the Monticello Association's president.

The association's position cuts no ice with the academic community. “This decision is scientifically unsound, historically unsound and morally bankrupt,” says Annette Gordon-Reed of the New York Law School. “The issue is pretty much settled and the fact that the family association chooses to tell a story about itself doesn't affect what scientists or historians think.”