A rabbi faces possible expulsion from the world's largest Orthodox rabbinical organisation for ordaining a female Orthodox rabbi.
Rabbi Avi Weiss, of New York, conferred the title "Rabbah" on Sara Hurwitz last month.
One of Rabbi Weiss's employees told NY Jewish Week that the Rabbinical Council of America (RCA) may now convene an ethics committee to decide how to respond.
The committee has the power to expel Rabbi Weiss from the RCA.
The conservative Orthodox group Agudath Israel has already
called the conferral of rabbinic authority on a woman "a radical and dangerous departure from Jewish tradition" that "must be condemned in the strongest terms".
The RCA did not respond to calls for comment.
Rabbi Weiss - a prominent activist on Israeli and Holocaust-related issues who was once named one of America's top rabbis by Newsweek - has been moving in the direction of female rabbis for some time. Last year he set up a school, Yeshivat Maharat, to train female rabbinic authorities.
But his involvement with women taking a prominent role in synagogue life goes back even further.
In 1998, he employed a woman as a congregational intern with some rabbinic duties at his synagogue, the popular Hebrew Institute of Riverdale.
At that time he told the New York Times: "I think the call for women rabbis is unhelpful, because there are roles that rabbis play that women, by Jewish law, are prohibited from doing. That's very clear. In the same breath, there are many other roles that women can perform."
Sara Hurwitz, who is originally from South Africa, started out as a congregational intern at the Hebrew Institute of Riverdale. Six years ago, she began studying the material covered in Orthodox rabbinical exams so that she could enhance her role there.
Last year she was ordained, but rather than give her a rabbinic title, Rabbi Weiss chose the title Maharat - an acronym for Manhigah Hilchatit Ruchanit Toranit, which means "leader in law, spirituality and Torah".
But in recent months Rabbi Weiss has complained publicly that the title "Maharat" was not working because Jews and non-Jews do not recognise it. Last month, he announced that henceforth, Hurwitz, 33, should be known as "Rabbah".
"This will make it clear to everyone that Sara Hurwitz is a full member of our rabbinic staff, a rabbi with the additional quality of a distinct woman's voice," Rabbi Weiss said.
Agudath Israel spokesman Rabbi Avi Shafran said the ordination of a woman ran counter to the concept of tzniut, or modesty.
"It includes the idea that women are demeaned, not honoured, when they are placed in the public eye," said Rabbi Shafran, "and that a position like the one suggested here is violative of that concept."
Rabbi Weiss did not return calls for comment.