A French Holocaust historian traveling to speak at a symposium at Texas A&M University was detained by immigration officials in Houston and nearly deported, according to The Eagle, a newspaper covering the College Station, Tex., area. The Washington Post and The Guardian also reported on the case.

Henry Rousso, an Egyptian-born French citizen, is a senior researcher at the French National Center for Scientific Research. Richard Golsan, the director of the Melbern G. Glasscock Center for Humanities Research at Texas A&M, reported at the symposium that Rousso had been “mistakenly detained” upon arriving Wednesday evening.

“When he called me with this news two nights ago, he was waiting for customs officials to send him back to Paris as an illegal alien on the first flight out,” The Eagle reported Golsan as saying. Golsan reported that Rousso was subsequently released after the intervention of a Texas A&M law professor and director of the university's Immigrant Rights Clinic.

Fatma Marouf, the director of the clinic, told The Guardian that Rousso entered the U.S. on a tourist visa. Generally, those entering on tourist visas cannot work or receive compensation, but there are exceptions for foreign nationals giving academic lectures or speeches.

"My best guess is that it was his honorarium. I don’t think the officer who decided to detain him really understood the visa requirement and the technicalities on getting an honorarium, which are permitted under his visa," Marouf told The Guardian.

Rousso, who studies the history of memory of World War II, tweeted about the experience and published a blog post in the French-language version of The Huffington Post.

“It is now necessary to deal with the utmost arbitrariness and incompetence on the other side of the Atlantic,” Rousso wrote, according to a translation by The Washington Post. “What I know, in loving this country forever, is that the United States is no longer quite the United States.”

I confirm. I have been detained 10 hours at Houston Itl Airport about to be deported. The officer who arrested me was "inexperienced" https://t.co/SdIKWKQbnr — Henry Rousso (@Henry_Rousso) February 26, 2017