I do know that the ignorant koranimals are behind it.
This paragraph from a 2001 internet article summarizes where the material came from... just Muslims being Muslims.
“While the world’s news media have kept quiet, the Arabs have hauled truckloads of dirt and debris out from under the south end of the Temple Mount, dumping it in the Kidron Valley. They destroyed any opportunity for archaeologists to explore the first and second Temple periods that were evident under the south end of the Temple Mount by paving the area and creating a huge Moslem prayer hall. Some Israeli archeologists are furious that the Barak administration could have allowed the desecration.”