It was there before the structure spontaneously decayed, on the eastern side of the statues, according to discoverer Bert Praxenthaler, an expert of renovation from the International Council on Monument and Sites.
The hemp sack is 5 centimeters in height and width and has what looks like a lion and horse clay great seal.
According to Buddhist doctrine, the lion and horse represent the Buddha himself.
The right hand of the statue is likely to have appeared after the destruction by the Taliban and the find was untouched.
One of the researchers from the team, Erwin Emmerling, a professor at Technical University of Munich, said, "This bag is supposed to be a present from India to celebrate setting up the Buddha, providing a hint to unveiling the mystery surrounding the creation of the statues."
In 2006, the same German group found a part of a Buddhist sutra in the rubble of the Buddhas after the destruction by Taliban.
Kosaku Maeda, a Wako University professor emeritus of Asian history who confirmed the finding, said the bag inside the eastern Buddha is very interesting because nobody has found anything inside the western Buddha yet.
"It will be an invaluable resource for studying Buddhist culture of Central Asia and for solving the mystery of Bamiyan," Maeda said.
