Mojtaba Doroudi said on Tuesday that the inscription was located on the hillside around the tomb of King Darius in Naqsh-e Rustam, and it has remained obscured since it was covered by sediments for the past two thousand years, IRNA wrote.
The discoverer of the ancient inscription highlighted, "The discovery is a historical achievent in the past half a century in the field of linguistics, Iranology and history."
The researcher recalled, "Naqsh-e Rustam's inscriptions were discovered and deciphered by Schmidt about 70 to 80 years ago."
He continued, "The inscription has not been seen so far and I saw it when I was taking pictures of the area.
"The text of this inscription is about one of the high-ranking figures of the Achaemenid court and ancient Persia, which has not been mentioned in history," said Davoudi.
Naqsh-e Rustam is an ancient necropolis located about 12 kilometers northwest of Persepolis, in Fars Province.