Three different independent auditors have supported that the pictures would be worth $20 million, if they were sold individually.
This has been difficult for regulators to swallow, since the donor would be receiving a break far greater than the amount that he actually spent.
Regulators have rejected the application for the break three different times, but the museum is attempting a fourth application.
The laws are different in the U.S. However, large donations will be carefully studied by tax officials.
