Asked if the excavation provided further evidence of the fact that Persepolis was the only major monument of ancient times that was built by paid workers and not by slaves, Professor Callieri replied, "No new information, not yet. We understand that one of the cities which had exchanges with the Persepolis Terrace was very near Persepolis. Probably it is the city we are going to excavate." However, he noted that in previous excavations tablets have been found that record the payments to the workers, and added that these "objective" documents prove the workers were paid.For those who don't understand the context here, Iranians are trying to prove that the Persian Empire under Cyrus and his successors outlawed slavery.
This is, of course, ludicrous, if only because every person in the Empire was in a very real sense the slave of the Shah. The King was the Law and nobody had any rights against him.
It is on the verge of being declared politically correct, as giving Iranians something to be proud about as opposed to those enslaving Greeks, Romans and other Europeans.