Some of the migrant families arrested at the southern border weren't actually families.

In a pilot program, approximately 30% of rapid DNA tests of immigrant adults who were suspected of arriving at the southern border with children who weren't theirs revealed the adults were not related to the children, an official involved in the system's temporary rollout who asked to be anonymous in order to speak freely told the Washington Examiner Friday.

"There’s been some concern about, 'Are they stepfathers or adopted fathers?'" the official said. "Those were not the case. In these cases, they are misrepresented as family members."

In some incidents where Immigration and Customs Enforcement told the adults they would have to take a cheek swab to verify a relationship with a minor, several admitted the child was not related and did not take the DNA test, which was designed by a U.S. company.

The pilot lasted a few days earlier this month and was used only in McAllen, Texas, and El Paso, Texas. ICE said the Department of Homeland Security would look at the results to determine if it will be part of its comprehensive solution to border issues. Homeland Security has not issued a public statement on its intentions going forward.

"This is certainly not the panacea. It’s one measure," said the official.

One upside, the source said, was that in addition to verifying bogus relationships, it also verified many when Homeland Security personnel were unsure.

The Examiner reported in March the Department of Homeland Security and ICE were looking at adopting the test, made by a company called ANDE. On May 1, DHS announced it would launch a pilot of the program in instances where ICE Homeland Security Investigations agents could not verify a family unit’s relationships.

The debut marked the first time DNA testing of any sort has been at the border. Currently, ICE and U.S. Customs and Border Protection must use verbal statements and written documents to verify family connections.