SALT LAKE CITY (AP) — The University of Utah is investigating a complaint that a convicted felon working at a fertility clinic replaced a customer's sperm with his own, and fathered a girl 21 years ago.

The girl's parents say they've were able to trace her lineage to clinic worker Thomas Ray Lippert, who's deceased.

Pamela Branum tells KUTV in Salt Lake City she doesn't think she and her husband were Lippert's only victims.

The university says there's "credible" evidence of sample tampering or mislabeling.