As world leaders paid tribute to Mandela at the memorial service on Tuesday, the international deaf community expressed outrage that the sign-language interpreter to the side of the podium was signing nonsense.

The male interpreter appeared to be provided by the ANC party. A female interpreter, provided by the broadcast station, could be seen in a box in the corner of the screen. Her interpreting was fine. You can see the difference between them in this clip:

Charlie Swinbourne at the U.K. deaf new news blog The Limping Chicken noted that something seemed strange about the way the male interpreter was signing. Different countries have different sign languages, so it is not unexpected for deaf people in different countries to have trouble understanding each other's interpreters, but his signing had "a strange repetitive rhythm," and "the structure of his hand and body movements didn't seem to change no matter what the speaker was saying."

It soon became clear that South Africans couldn't understand him either.

World Federation of the Deaf Vice President Wilma Newhoudt, who is also the first deaf person elected to the South African Parliament, asked representatives of the ANC to get the interpreter off the stage.

Braam Jordaan, who is a deaf South African and a board member of the Youth Section of the World Federation of the Deaf, told SBS Australia that the interpreter "made up his own signs" and "what happened at the memorial service was a disgraceful thing to see."

Adding insult to injury, this is probably not the man's first offense. According to Gerald Lynch at Gizmodo UK, the phony interpreter "is thought to have been a regular at many South African governmental public events."

So how did this man get on stage? The deaf community is still waiting for an explanation from the ANC. When asked whether she would raise the matter with the ANC and South African government, Newhoudt responded this way: