This is book number 1932 in the Ellery Queen Mysteries (Audio) series.
In one of his earliest cases, Ellery Queen confronts a murder in blue blood.
From the very beginning, the Khalkis case struck a somber note. It began, as was peculiarly harmonious in the light of what was to come, with the death of an old man. Georg Khalkis, internationally famous art dealer and collector, died of heart failure. After his funeral, his attorney found that the will was missing and immediately called in the district attorney.
When Inspector Queen and his son, Ellery, are brought in to solve the mystery, Ellery mentions the one place they have not searched for the will: the coffin. Upon exhumation of the Khalkis coffin, they find that it contains not one body-but two