The troubled J. Paul Getty Trust has been put on probation by the US body responsible for charitable foundations.
The trust, which oversees the famous Getty Museum in Los Angeles, failed to hand over information needed for a review of its financial practices.
The 60-day probation carries no penalties but is a further blow to the trust which recently returned artworks that were allegedly stolen from Italy.
An ex-curator of the Getty museum was charged with trafficking last month.
Marion True, together with art dealer Robert Hecht, appeared in court in Rome to deny two separate charges involving 35 artefacts bought between 1986 and the late 1990s.
Ms True resigned after Getty officials confronted her about a $400,000 (£225,000) loan she received from a pair of art collectors days after the museum completed a deal to acquire their collection.
Greece has also alleged that the Getty Museum has artworks that were taken from the country.
The Getty has said it had tried to get the documents required to the US Council on Foundations, which began its inquiry into the Getty Trust in June following a newspaper report that alleged lavish spending by chief executive Barry Munitz.
The council, which has some 2,000 non-profit members, implemented a stricter ethics policy last year that requires a confidential, outside review whenever misconduct allegations are made against a member.