“Unfortunately, some in the community are resistant to sharing the name of the mohels,” Health Department spokesman Christopher Miller told DNAinfo New York on Tuesday. “This is a very insular community.”

According to DNAinfo, six families in Williamsburg, Brooklyn, have seen children contract herpes since 2015 from metzitzah b’peh, which involves the ritual circumciser, or mohel, cleaning the circumcision wound by oral suction. Among the six families, only two have provided the names of their mohels, Miller said.

In March, the city ordered those two mohels to stop performing metzitzah b’peh. A herpes infection in a newborn baby can cause brain damage and death.

Rabbi David Niederman, head of the United Jewish Organizations of Williamsburg and North Brooklyn, told DNAinfo that the community was “fully cooperating” with the investigation. However, an unnamed source said the community is skeptical about the allegations against the two named mohels because it believes the city wants to make all metzitzah b’peh illegal.

“That’s why we’re not willing to give out the mohels. We know the city is going to ban them without giving them due process,” the source said. “There is not proof that they actually infected the baby.”

The custom, rarely practiced outside the haredi, or fervently Orthodox, community, has become a political football in New York City with its large haredi population. In February 2015, the city eliminated a parental consent form mandated by former Mayor Michael Bloomberg. In return, the community pledged to test a mohel after an infant contracts herpes.

City Health Commissioner Dr. Mary Travis Bassett said her department considers metzitzah b’peh an “unsafe practice,” but that as a religious practice it enjoys several legal protections.