The search of museums in Greece and elsewhere in Europe follows the discovery by a leading Greek architectural historian that three magnificent statues of Victory appear to have dominated the roof of the Parthenon for the first 600 to 900 years of its history.
A survey by Dr Manolis Korres of the 2,440 years old Temple of Athene suggests that at three of the building's corners, the ancient architects placed 8ft statues of Winged Victory.
Careful examination of the roof showed that slabs of masonry each weighing four tons had been placed at the corners as counterweights to prevent the statues falling over. Three of the slabs also appear to have once had iron "anchors" embedded in them to keep the statues stable.
The lost Parthenon statues would have been the same size, period and style as the Olympia Winged Victory (in Olympia Museum) - the most precious classical statue of Victory in the world. The Winged Victory of Samothrace, in the Louvre, is 250 years later and more sophisticated.
The victories would have leant forward, with one foot on the roof, the other in mid-air. Each is thought to have weighed about a ton, making them some of the largest Parthenon sculptures. Similar winged victories have been found among the ruins of a temple on the island of Delos, built by one of the architects who designed the Parthenon.
The statues were probably stolen by Roman antique dealers or destroyed by anti-pagan Christians between the 2nd and 6th centuries AD. Fragments of the broken sculptures may have lain around the Parthenon for centuries.
The first systematic removal of sculptural fragments took place in the 17th century, when German, Hungarian, Austrian and Swedish mercenaries fighting for the Venetians carted off large quantities of broken sculpture lying on the ground.
Then, in the late 18th century, a French antiquarian carried out rudimentary excavations and removed further sculptures. In the early 19th century, a senior British diplomat, Lord Elgin, removed vast amounts of other material, including the fragments of the Parthenon frieze now in the British Museum, known as the Elgin Marbles.
Only three corners of the Parthenon appear to have been graced with a winged victory. The southwest corner does not seem to have had one. There is a counter-balancing stone slab, but there is no sign of there ever having been any metal pegs.
Dr. Korres believes that a war between Athens and Sparta which broke out in 431 BC prevented the installation of the fourth statue.
Dr Korres, who has just written a book on the construction of the Parthenon, has also discovered structural evidence which shows that the "Elgin Marbles" frieze was never envisaged by the temple's original designers. The 360- figure frieze seems to have been added as an afterthought. Parts of the Parthenon's walls and some of the inner columns had to be dismantled and redesigned to adjust to the new plan.
He believes that the decision by the Athenian authorities to change their plans reflects a shift in the balance of political power in the city.The frieze is thought to represent the political and cultural practices and aspirations of the people of 5th-century BC Athens - and was at the time a controversial and revolutionary concept, artistically and politically.
Dr Korres has also found new evidence showing how the Parthenon was constructed. He has, for instance, found six tiny 4-6 mm diameter metal rollers in hollows high up in the structure. They were used to roll carved masonry elements into position on top of columns.
He has also discovered how the column drums were made to fit together. He found fragments of "leveling" plates. Each 6 cm thick plate would have been covered with red paint and laid on top of column drum surfaces. Those higher areas which picked up the paint were then earmarked for further grinding.
Dr. Korres' book, From Pentelicon To The Parthenon, is published by Melissa at £25. An exhibition based on the book is at The Foundation for Hellenic Culture, 60 Brook Street, W1, until 31 March.