As reported in the Turkish newspaper Sabah, Radi Dikici, one of Turkey's most eminent Byzantinists [among his books are Bizans İmparatorluğu Tarihi (History of the Byzantine Empire), Şu Bizim Bizans (This Our Byzantium) and a novel titled Empress Theodora] believes that a portion of the True Cross discovered by Empress Helen in the fourth century and brought to Constantinople still resides somewhere in the area of Hagia Sophia, in a hidden location.
Historical accounts record how Empress Helen, upon discovering the Cross outside the walls of Jerusalem, left a portion of it in Jerusalem and brought the rest back to Constantinople together with the nails. Eventually it was placed in Hagia Sophia for veneration. According to the Turkish historian Radi Dikici, there is testimony that when the Crusaders sacked Constantinople in 1204, certain Byzantine dignitaries and priests took the Holy Cross and hid it in a secret place within Hagia Sophia. While Constantinople was under the Latin yoke, eventually those who hid the Cross died and its location has remained hidden ever since. Radi Dikici believes that the True Cross remains hidden somewhere within Hagia Sophia.
Whether or not the True Cross of Christ is indeed hidden within Hagia Sophia today remains a mystery, but it is also interesting that such a story is not only being explored by a Turkish Byzantinist, but that it was circulated in one of Turkey's most popular daily newspapers. It is yet more proof of Turkey's growing interest in Orthodox Christianity and their Roman Orthodox roots.