"Excavators also removed a layer of mud roughly 4 centimeters (1.5 inches) thick from inside the coffin that Fényes hopes could contain more treasures."
i strongly suspect this is not "mud" but the dried precipitate of liquified soft tissue, [coffin liquor] and condensation.
limestone is porous and will allow water to eventually seep through.
a condensation cycle will occur, and drip percolate the soft tissue and adipocere into a slurry [coffin liquor] that will settle to the bottom of the sarcophagus.
"Excavators also removed a layer of mud roughly 4 centimeters (1.5 inches) thick from inside the coffin that Fényes hopes could contain more treasures."
i strongly suspect this is not "mud" but the dried precipitate of liquified soft tissue, [coffin liquor] and condensation.
Where did the mud inside come from if it was still sealed?
limestone is porous and will allow water to eventually seep through.
a condensation cycle will occur, and drip percolate the soft tissue and adipocere into a slurry [coffin liquor] that will settle to the bottom of the sarcophagus.