Sensing equipment, capable of electronically detecting underground chambers, is being used to locate any burial chambers that may exist beneath the main structure of the tomb.
Professor Abdel Halim Nur el Din, secretary-general of Egypt's archaeological authority, said yesterday he was hoping that Alexander's mummy would be found. "The evidence points to the tomb being that of Alexander the Great. But I must stress that the archaeologists are only beginning excavations."
Five key pieces of evidence linking the tomb to Alexander, who expressed a wish to be buried at Siwa, have been found. The most telling are three broken stone tablets that appear to refer to Alexander. A preliminary translation of the largest one - almost certainly composed by Alexander's successor as ruler of Egypt, Ptolemy I - reads: "I present these sacrifices according to the orders of the god and carried the corpse here - and it was as light as a small shield - when I was commander of Egypt. It wasI who was caring about his secrets, and who was carrying out his wishes. I was honest to him and to all people and as I am the last one still alive I state that I have done all the above for his sake."
A smaller tablet refers to 30,000 soldiers being told to guard the tomb. This is symbolic and probably refers to the 30,000 "Successors" Alexander recruited in Persia to safeguard the destiny of his empire.
The tablets, inscribed in Greek, appear to date from around 30 years after Alexander's death in 323 BC, but a third is Roman, dates from the early 2nd Century AD and suggests the tomb was a centre for a cult of Alexander.
The archaeologists, led by Liana Souvaltzis, of the Athens-based Institute of Hellenistic Studies, also found an eight-pointed star in the tomb - the symbol of Alexander's Macedonian royal family. The tomb is built on classic Macedonian lines - and at 51metres in length it is bigger than any of the royal tombs in ancient Macedonia.
Historians previously believed Alexander had been buried in Alexandria.