The parents of a 21-year-old girl say they were shocked to discover that a fertility clinic worker was their daughter’s biological father.

The Branum family say they thought it would be fun to do a home DNA test in order to learn more about their genealogy. But when they got back the results, they say they found that 21-year-old Annie Branum was not biologically related to her dad.

According to the Branums, Thomas Ray Lippert, a former fertility worker at a now-shuttered clinic at the University of Utah, swapped in his own sperm. Lippert has since passed away.

Mother Pamela Branum says the worker had a board filled with dozens of baby pictures and that he told her that those were the babies he had helped couples have. She says his comments took on a whole new meaning for her after the DNA test.

The university says it has been investigating these claims since April. Officials at the university say two other families have contacted them with concerns over the same worker.

Though this revelation was tough on the family, Annie told Shepard Smith, “I think it has definitely brought us closer together.”