A self-styled arts philanthropist facing federal sex-tourism charges was ordered Thursday to be detained until trial.

Kenneth Schneider, 45, the founder of the Apogee Foundation, was extradited from Cyprus to Philadelphia last week on charges that between 1998 and 2004 he had a sexual relationship with an underage ballet dancer in Russia who was under his financial sponsorship. The indictment also alleges that he continued the assaults after bringing the boy to Philadelphia to study at the Rock School in 2001.

In his decision, U.S. District Court Judge Thomas M. Golden ruled that Schneider, an international businessman, was a flight risk because of his extensive contacts in countries that do not have extradition treaties with the United States.