On Wednesday, the FBI executed a search at Dane Fine Art, a gallery based in Ardmore, Pennsylvania. While the FBI did not say what the search was for, a spokesperson told CBS Philadelphia that it was conducting a “court-authorized law enforcement activity.”

Victor Fiorillo, a senior reporter at Philadelphia magazine, was on the scene of the search Wednesday, reporting that he “witnessed several FBI agents going in and out of the two-story building.” When Fiorillo approached, an agent told him that they were executing a search warrant.

After the search was over, a handwritten note on the door listed a phone number; when Fiorillo called it, a gallery employee told him the gallery was “closed” for the day but did not know why.

While Dane Fine Art has been around for many years, it’s not clear who the owners are. Fiorillo did some sleuthing in property records and found that the gallery’s incorporation documents include a mailing address for a property once owned by Leslie Isen, the wife of art collector Nathan “Nicky” Isen, who previously ran the now-defunct gallery I. Brewster & Company.

Isen also pleaded guilty in 2015 to money laundering in a scheme where he used art to allegedly launder drug money. That same year, Philadelphia magazine published a deep dive into Isen. That piece detailed allegations that Isen sold fake artworks, though none of it has been proven.

Dane Fine Art advertises on its website that it sells work by numerous blue-chip artists, including Andy Warhol, Alexander Calder, Alex Katz, Ellsworth Kelly, Keith Haring, Henri Matisse, and Jean-Michel Basquiat, to name just a few of those listed on its artist page.

On Thursday, the gallery held an online auction titled “Dog Days of Summer Modern & Contemporary Sale,” offering what it said were original prints by Warhol, Haring, Renoir, and others.

When contacted by ARTnews on Thursday, a gallery employee responded, “No comment,” to questions about the FBI search. When asked to confirm whether Isen is the owner of Dane Fine Art, the employee hung up.