JOHANNESBURG – The man accused of faking sign interpretation while standing alongside world leaders like U.S. President Barack Obama at Nelson Mandela’s memorial service said Thursday he hallucinated that angels were entering the stadium, has schizophrenia and has been violent in the past.

Thamsanqa Jantjie said in a 45-minute interview that his hallucinations began while he was interpreting and that he tried not to panic because there were “armed policemen around me.” He added that he was once hospitalized in a mental health facility for more than 1½ years.

The statements by Jantjie also raise serious security issues for Obama, other heads of state and United Nations Secretary-General Ban Ki-moon, who stood next to Jantjie as they made speeches at FNB Stadium in Soweto, Johannesburg’s famed black township. The ceremony honored Mandela, the anti-apartheid icon and former president who died on Dec. 5.

A South African deputy Cabinet minister, Hendrietta Bogopane-Zulu, later announced that “a mistake happened” in the hiring of Jantjie. However, many questions remain, including who in the government hired the company that contracted Jantjie, how much money the government paid the company and Jantjie’s own involvement with the company – and even whether it really exists.

Government officials said they have tried to track down the company that provided Jantjie but the owners “have vanished into thin air,” said Bogopane-Zulu.

She apologized to deaf people around the world who were offended by Jantjie’s incomprehensible signing.