Under federal law, museums must return any remains and spiritual objects that can be reasonably traced to a tribe.
Under this new policy, if a government could prove an object had been illegally exported, the museum would return it.
Robert Bishop, the museum's director, said he had always been certain that the museum would return to its old address.
The school board recently voted to take legal action if the museum does not return the painting.
In the past, the museum would have returned all the works when the show closed.
In 1951, the museum returned to its building that had been restored.
Beginning in January 2007, the museum returned to free general admission with the exception of special exhibits.
Those museums did not return phone calls asking for comment.
Perhaps as important, the museum is returning to the foundation 92 works, valued at about $55 million, from the collection.
The museum did not return calls to discuss the audit.