The question of whether the marriage of a woman to her “half-blood” uncle should be voided for incest under New York’s Domestic Relations Law will go to the New York Court of Appeals.

The U.S. Court of Appeals for the Second Circuit on Wednesday certified that question to New York’s highest court in the immigration case of Nguyen v. Holder, 13-605-ag.

The circuit said there was “substantial evidence” supporting a decision by the Board of Immigration Appeals to uphold an immigration judge’s removal order for Huyen Nguyen, a citizen of Vietnam who was admitted as a conditional permanent resident in 2000 based on her marriage to Vu Truong, a U.S. citizen.

Nguyen was later charged as removable because the government found evidence that she was Truong’s half-niece—specifically, that Truong is the half-brother of Nguyen’s mother.

The Board of Immigration Appeals affirmed an immigration judge’s conclusion that “a marriage between a niece and half-uncle is invalid under New York law.”

But the circuit said there was some ambiguity, and there was no reported decision by the New York Court of Appeals that “squarely holds that section 5(3) of New York’s Domestic Relations Law prohibits marriages between half-blooded nieces and uncles.”