The South African government is facing embarrassing questions after it was revealed that the man they employed to translate proceedings at the memorial for Nelson Mandela - including speeches by world leaders - was a fake.

The man, seen in the video below, appeared to be taking his job very seriously, but was apparently simply making a series of meaningless gestures, infuriating deaf and hearing-impaired viewers of the event.

Sky News quoted "three sign language experts" as confirming that the man was not signing in any recognizable South African or American languages.

"It was horrible, an absolute circus, really really bad," said official sign language interpreter Nicole Du Toit. "Only he can understand those gestures."

But the gaff has a more serious side to it. The clear lack of a proper vetting process for a man given such close proximity to world leaders including US President Barack Obama presented a major security risk.

South African Authorities are attempting to track the man down, but so far his identity is unknown.