Thamsanqa Jantjie also told The Associated Press that he was undergoing a medical examination Tuesday at the Sterkfontein Psychiatric Hospital west of Johannesburg. The hospital declined to confirm that he was there, saying it cannot divulge information about patients.
A cousin and three friends of Jantjie have said he was part of a mob that accosted two men found with a stolen television and burned them to death by setting fire to tires placed around their necks in 2003. They said he never went to trial for the 2003 killings when other suspects did because authorities determined he was not mentally fit to stand trial.
Jantjie has said he has schizophrenia and hallucinated during the Dec. 10 stadium memorial for Mandela, in which he made arm and hand movements that experts said were gibberish. Mandela died Dec. 5 at age 95, and the memorial was part of an extended mourning period for the anti-apartheid leader and former president.
On Tuesday, Jantjie told the AP in a telephone interview that he had been hired by a company called South African Interpreters, which had used him on a freelance basis for years.
"Everyone knows I am an interpreter. I've been interpreting for years, at big events, even for the government and the ANC," he said. The African National Congress was the liberation movement during the fight against white rule in South Africa, and has dominated politics since Mandela became president in the first all-race elections in 1994.
Jantjie said he had records to prove that South African Interpreters had hired him, and said the wife of company owner, Bantubahle Xozwa, had accredited him for the Mandela memorial.
The Sunday Times, a South African newspaper, quoted Xozwa, who is also the head of a religious and traditional affairs agency of the ANC, as saying Jantjie had interpreted at the memorial in his personal capacity.
Xozwa told the newspaper that Jantjie was an administrator in his company but was not an interpreter because he was "was disqualified years ago on the basis of his health."
The AP was unable to reach Xozwa for comment on Tuesday.
South African government officials have not said how long the investigation into Jantjie, and whether he received security clearance, will take.
The ANC has said it had no role in hiring Jantjie for the memorial, but has acknowledged using him at events in the past.
Four government departments involved in organizing the memorial service have also distanced themselves from Jantjie, telling the AP they had no contact with him. A fifth government agency, the Department of Public Works, declined to comment and referred all inquiries about Jantjie to the office of South Africa's top government spokeswoman, who has only said a "comprehensive report" will eventually be released.
Jantjie has admitted to a history of mental problems and "violent episodes" in the past and that he had been a patient in a psychiatric institution for more than a year. He was discharged and started working after being medicated and monitored by doctors.
After the memorial at FNB Stadium in Soweto on Tuesday, Jantjie told various media outlets he had suffered a schizophrenic episode in which he had seen angels, and that he had panicked when he realized he was surrounded by armed police.