A day earlier, he told the AP that he had been violent "a lot'' in the past, has schizophrenia and hallucinated during the Mandela memorial that angels were descending into the stadium. He also apologized for his performance, but defended his interpreting as "the best in the world.''
His assertion was ridiculed by deaf advocates who said he didn't know how to sign "Mandela'' or "thank you.''
The outcome of the reported murder case that eNCA said dated from 2003 was unclear, and the television report did not disclose any details.
Officials at the Johannesburg court where the murder charge was reportedly lodged were not in their offices Friday afternoon and did not respond to email requests seeking comment.
There were no records of a murder case involving Jantjie at South Africa's National Prosecuting Authority, but spokesman Nathi Mncube said that doesn't necessarily mean Jantjie was never a suspect.
"I cannot confirm that the guy was charged, but I cannot deny it, either,'' he said. "There are no records right now.''
Jantjie also faced other lesser criminal charges in the past, eNCA reported. In the interview with the AP, he blamed his past violent episodes on his schizophrenia, but declined to provide details.
The fiasco surrounding the use of Jantjie to provide sign language translation before a worldwide television audience has turned into an international embarrassment for South Africa, whose ruling party, the African National Congress, and president, Jacob Zuma, have already lost popularity because of corruption scandals and other public grievances. But the ANC is far more powerful than the opposition and Zuma, who was booed at the Mandela memorial, is likely to be its candidate in elections next year.
The U.S. assistant secretary of state for African affairs, Linda Thomas-Greenfield, said Friday that "we're all very upset'' about Jantjie, who was just 3 feet from Obama at the memorial service for Mandela, who died December 5 at 95.
Thomas-Greenfield told reporters in Kenya that U.S. officials are concerned about security and how Jantjie could have gotten so close to world leaders. She said officials were also dismayed because people watching around the world who needed sign language weren't able to understand what was said at the ceremony. She called the problem "extraordinarily sad.''
South Africa's arts and culture minister, Paul Mashatile, apologized for the use of Jantjie on Friday, marking the second apology from the government in two days, and said reforms must be implemented to ensure such an incident doesn't happen again.
"Without passing judgment, nobody should be allowed to undermine our languages. We sincerely apologize to the deaf community and to all South Africans for any offense that may have been suffered,'' Mashatile said in a statement.
He did not comment on who was responsible for hiring the sign interpreter.
Four government departments involved in organizing the historic memorial service distanced themselves from the hiring of Jantjie, telling the AP they had no contact with him.
A fifth government agency, the Department of Public Works, declined comment and referred all inquiries about Jantjie to Williams' office.
Williams said the investigation would include trying to determine who hired Jantjie or the company he said he worked for. She did not say how long the probe might take, and police spokesman Lt. Gen. Solomon Mogale said there would be no additional information released until after Mandela's funeral Sunday in his hometown of Qunu.
The government is also trying to determine how Jantjie received security clearance and what vetting of his background if any took place. Officials at the State Security Agency, in charge of security for the event, have not commented publicly and by Friday had not responded to questions submitted by email a day earlier by the AP.
The government says the owners of the interpreting company have disappeared, and the AP was unable to track down the school where Jantjie said he studied signing for a year. An online search for the school, which Jantjie said was called Komani and located in Eastern Cape Province, turned up nothing.
Ingrid Parkin, principal of the St. Vincent School for the Deaf in Johannesburg, said she and other advocates for the deaf had never heard of the school. She added that there are no known sign language institutes in the province.
The Star newspaper of Johannesburg reported Friday that Jantjie said he studied sign language interpretation in Britain at the "University of Tecturers.''
"We're not aware of that university,'' said Emma Mortimer, communications director of Signature, a charity that awards qualifications in deaf and deaf-blind communication techniques.
Even if he had studied in the United Kingdom, Mortimer said that wouldn't necessarily qualify him to work in South Africa because the country's two sign languages are different.
"It would be like you going to France and speaking English,'' she said.
- AP writers Tendai Musiya and Gerald Imray in Johannesburg, Danica Kirka in London and Jason Straziuso in Nairobi, Kenya, contributed to this report.