Deaf organisations have complained after the man translating the speeches at Nelson Mandela's memorial service, including President Obama, was allegedly revealed to be fake.
ITV News International Correspondent John Irvine reports:
The sign language interpreter "made up his own signs" South Africa's deaf federation said.
Ingrid Parken, the principal of a Johannesburg school for the deaf, said she had to leave the room where she was watching the service because she was so disgusted by what she saw during the service as the man was "talking gibberish".
The government, which was officially in charge of the ceremony said it did not know who the man was.
"Government is looking in to this matter but has not been able to conclude this inquiry due to the demanding schedule of organising events," Presidency Minister Collins Chabane told a news conference.
Jacob Zuma's spokesman Mac Maharaj said he was checking the reports, while the SABC state broadcaster, which covered the memorial, said it was not involved as it had its own on-screen signers.
Video posted online appears to show the man 'interpreting' for South African president Jacob Zuma last year.
The footage, apparently filmed in January 2012 at the ANC party's 100th anniversary, shows the man making gestures as Zuma sings to the crowd.
ANC communications manager Keith Khoza told NBC News that the interpreter had translated for party events in the past, but said that the man only “volunteered” and was not paid.