The White House has downplayed fears that Thamsanqa Jantjie was a security risk
The signer at Nelson Mandela's memorial - accused of making up gestures - has been admitted to a psychiatric hospital, local media report.
Thamsanqa Jantjie "might have had a breakdown", his wife Siziwe is quoted as saying.
Sign language experts accused him of referring to "prawns" and "rocking horses" while translating eulogies at Mr Mandela's memorial last week.
Mr Jantjie said he suffered a sudden attack of schizophrenia.
He insisted he was a qualified interpreter.
Thamsanqa Jantjie explains his schizophrenic episode
South Africa's Deputy Disability Minister Hendrietta Bogopane-Zulu has said the company which had employed him had "vanished".
Mr Jantjie's wife took him to a psychiatric hospital near Johannesburg for a check-up on Tuesday, and it was suggested that he be admitted immediately, Johannesburg's The Star newspaper reports.
"The past few days have been hard. We have been supportive because he might have had a breakdown," Mrs Jantjie is quoted as saying.
Last week, Mr Jantjie said he was supposed to have gone for a check-up on the day of the memorial, but he postponed it.
During the memorial at Johannesburg's FNB stadium, which was broadcast live around the world, Mr Jantjie stood on the stage next to key speakers including US President Barack Obama, South African President Jacob Zuma and Mr Mandela's grandchildren, translating their eulogies.
Mr Jantjie blamed his flawed interpretation on a schizophrenic episode, saying he had seen angels coming into the stadium.
The White House has downplayed fears that he was a security risk to Mr Obama.
Sign language experts said he had made "funny gestures" and little more than "flapping his arms around".
The governing African National Congress (ANC) said it had used Mr Jantjie as an interpreter several times before, and "had not been aware of any complaints regarding the quality of services, qualifications or reported illnesses" of the interpreter.
Mr Mandela died on 5 December at the age of 95 and was buried on Sunday.