* Interpreter says he is not a failure
* South Africans continue to mourn Mandela
* Mandela's body lie in state in Pretoria
A South African sign language interpreter accused of miming nonsense as world leaders paid tribute to Nelson Mandela defended himself as a "champion" signer on Thursday, but said he suffered a schizophrenic episode during the event.
The interpreter, 34-year-old Thamsanqa Jantjie, told Johannesburg's Star newspaper he started hearing voices and hallucinating while on stage, resulting in gestures that made no sense to outraged deaf people around the world.
"There was nothing I could do. I was alone in a very dangerous situation. I tried to control myself and not show the world what was going on. I am very sorry. It's the situation I found myself in," he told the paper.
He did not know what triggered the attack, he added, saying he took medication for his schizophrenia.
Millions of TV viewers saw Jantjie interpreting for leaders including U.S. President Barack Obama and his South African counterpart, Jacob Zuma, at Tuesday's Mandela memorial.
Afterwards South Africa's leading deaf association denounced Jantjie as a fake who was making up gestures as he stood yards away from world leaders.
The controversy has raised awkward questions over security at the event and cast a shadow over South Africa's 10-day farewell to Mandela, whose remains were lying in state for a second day on Thursday at Pretoria's Union Buildings, where he was sworn in as the nation's first black president in 1994.
It also heaps more pressure on Zuma, who was booed by the crowd on Tuesday after a slew of corruption allegations against him and his administration. Footage from two large ANC events last year shows Jantjie signing on stage next to the president.
The government, which was in charge of the mass memorial, said it had no idea who he was, a comment echoed by Zuma's ruling African National Congress (ANC).
In a radio interview, Jantjie said he was happy with his performance at the memorial to the anti-apartheid hero, who died a week ago aged 95.
"Absolutely, absolutely. I think that I've been a champion of sign language," he told Johannesburg's Talk Radio 702.
When contacted by Reuters, he said he could not understand why people were complaining now, rather than after other events. "I'm not a failure. I deliver," he said, before hanging up.
The publicity surrounding Jantjie's unconventional gestures - experts said he did not know even basic signs such as "thank you" or "Mandela" - sparked a frenetic hunt for the interpreter.
Jantjie said he worked for a company called SA Interpreters, hired by the ANC for Tuesday's ceremony at Johannesburg's 95,000-seat Soccer City stadium.
Attempts by Reuters to track down the company were unsuccessful, and the ANC denied any knowledge.
"I'm very, very surprised," spokesman Jackson Mthembu said. "We will follow this up. We are not sure if there is any truth in what has been said."
The death of Nobel peace laureate Mandela triggered an outpouring of grief and emotion - as well as celebration and thanksgiving - among his 53 million countrymen and millions more around the world.
Thousands of mourners continued to queue to say goodbye to Mandela in the capital, although that too has not been without its problems.
A lack of drinking water and toilets caused several people to pass out on Wednesday, and on Thursday social media reports emerged saying some mourners had taken photographs of Mandela's body, defying the wishes of his family and the government.
A official statement urged people to delete any pictures of Mandela's remains if they existed. It also said there were no plans to release an official photograph of Mandela lying in state.
His body will lie in state for a third day on Friday before being flown to the Eastern Cape, where it will be buried on Sunday at his ancestral home in Qunu, 700 km (450 miles) south of Johannesburg.t.