The Getty Museum paid roughly $10 million for a towering marble statue of an archaic Greek youth and eventually had to admit it could not say whether it was ancient or modern. This episode unravels the forensic mystery of the Getty Kouros, which arrived in seven pieces in 1983 from Basel dealer Gianfranco Becchina with a provenance file that fell apart almost immediately, including a 1952 letter bearing a postal code that did not exist until 1972 and a 1955 letter citing a bank account opened in 1963.

We explain why forged paperwork does not automatically mean a forged statue, then walk through the stylistic evidence that spans nearly a century from the hair to the feet, the anatomical quirks that argue for authenticity, the fine point tool marks that argue against it, and the geochemistry. Norman Herz traced the marble to Thasos, Stanley Margolis’s dedolomitization findings seemed to prove ancient weathering, and then Marilyn Kastner reproduced the same crust in a lab within months.

• Why trustee Federico Zeri resigned in 1984 over the decision to buy despite the fake documents
• How Gisela Richter’s classification system exposes a statue whose style ages backward from head to toe
• The lectio difficilior argument that the mismatched styles are too strange for a forger to invent
• The subtle turn in the stance that scholar Ilse Kleemann sees as evidence of genuine temple architecture
• The proven fake torso made of the same Thasian marble and why the Getty bought it to study side by side