The unidentified man was standing on stage next to world leaders including President Obama.
A leader of the Deaf Federation of South Africa confirms the man was “moving his hands around but there was no meaning in what he used his hands for."
The Associated Press reports there has not been confirmation that the man was a fake but the South African government is preparing a statement.
There was confusion at first about whether the man was signing in a language that was not widely known.
But three separate sign language experts watching the telecast confirm the man was not using any South African or American sign language.
Nicole Du Toit is a real sign language interpreter, she told the AP "it was horrible, an absolute circus, really really bad. Only he can understand those gestures."