CHICAGO (WGN) – The president of the Art Institute of Chicago is on voluntary leave from the museum after an alleged incident on a United Airlines flight last month.

On Friday, April 18, James Rondeau flew from Chicago to Germany. When the plane landed in Munich, police were called after he had allegedly taken off his clothes, CBS News first reported. Sources for the outlet claimed the incident occurred after Rondeau took prescription medication and drank alcohol.

A spokeswoman for the Art Institute confirmed the report and issued the following statement to affiliate WGN:

“The Art Institute takes this very seriously and has opened an independent investigation into the incident to gather all available information. And to clarify, James will voluntarily be taking time way from the office while the investigation is completed.”

The Art Institute of Chicago was established in 1879 and houses such works as Edward Hopper’s “Nighthawks,” Grant Wood’s “American Gothic,” and Georges Seurats’ “A Sunday at La Grande Jatte.”

Rondeau has been the president and director of the museum since 2016, according to its official website. Both the Chicago Sun-Times and the Chicago Tribune estimate his annual salary at over $1 million, citing recent tax records.