A corruption investigation into the Mexican president’s extended family could slow plans to open a high-tech customs “port” that would clear trucks for export to Mexico in the heart of the Midwest.

The customs facility, which U.S. and Mexican officials are planning to open in Kansas City, Mo., in May, would be the first customs house run by a foreign country inside the United States.

Customs agents from both countries would work to inspect and seal big rigs full of export goods, and shoot the trucks back out onto the North American Free Trade Agreement corridor, where they could cross the border without delay.

But in the wake of a corruption probe involving the sons of Mexico’s first lady, a Mexican congressional commission now is considering requesting a formal briefing on the Kansas City project and the national customs system. A separate congressional investigation is examining whether the first lady’s sons were involved in importing contraband goods from China.