JOHANNESBURG — A man who provided sign language interpretation on stage for Nelson Mandela's memorial service, attended by scores of heads of state, was a "fake," the national director of the Deaf Federation of South Africa said on Tuesday.

Asked about the claim by The Associated Press, South Africa's government said it was preparing a statement.

Three sign language experts said the man was not signing in South African or American sign languages. South African sign language covers all of the country's 11 official languages, according to the federation. It wasn't immediately clear if the unidentified man was using a different method to communicate.

The unidentified man seen around the world on television next to leaders like President Barack Obama "was moving his hands around but there was no meaning in what he used his hands for," said Bruno Druchen, the federation's national director.

Nicole Du Toit, an official sign language interpreter who also watched the broadcast, said in a telephone interview that the man on stage purporting to sign was an embarrassment.

"It was horrible, an absolute circus, really bad," she said. "Only he can understand those gestures."

South African parliament member Wilma Newhoudt, a member of the ruling party who is deaf, also said the man communicated nothing with his hand and arm movements.

AP interviewed both Druchen, who also is deaf, and Newhoudt by telephone using an interpreter.