UNITED STATES (AP) – The U.S. government’s DNA testing of migrant families separated at the Southwest border has turned up some surprises.

A Health and Human Services official said Tuesday that in two cases adults who thought they were parents of a child were determined not to be by DNA testing.

Chris Meekins is helping to direct the court-ordered family reunifications of migrants seeking asylum in the U.S. He says the adults “may not realize they’re not the biological parent.”

It was unclear how the surprises would be dealt with.

The government is using DNA testing – done by swabbing inside the cheek – along with documentation such as birth certificates and passports to reunite children with parents.