Millions around the world watched Thamsanqa Jantjie, 34, 'waving his hands aimlessly' next to Barack Obama at Tuesday's ceremony as he pretended to interpret the U.S. president's tribute to Mandela for deaf viewers.
Now, days after it was claimed he has faced charges for murder, rape and kidnapping, the four sources said he was part of a vigilante execution squad who placed tyres around their victims' necks and set them ablaze - a horrific practice known as 'necklacing'.
They say Jantjie was institutionalized and then returned to his neighborhood on the outskirts of Soweto.
The accusations come days after it was claimed he has faced charges for murder, rape and kidnapping.
VIGILANTE JUSTICE IN SOUTH AFRICA: WHAT IS NECKLACING?
It can often take a victim more than 20 minutes to die in excruciating agony.
In the violent 1980s and 1990s, necklacing was a common sentence imposed by 'people's courts' on collaborators with the apartheid regime and criminals in South Africa.
It was frequently carried out in the name of the African National Congress and was alleged to have been endorsed by Nelson Mandela's then wife, Winnie. The ANC says it never condoned necklacing.
In 1986 Mrs Mandela, caused controversy when she stated: 'With our boxes of matches and our necklaces we shall liberate this country.'
The statement, which was widely seen as an implicit endorsement of necklacing, caused the ANC to briefly try to distance itself from her.
It is still used in certain, more lawless, parts of Africa, where corrupt police are no longer trusted, to punish thieves and rapists.
Incidents have been reported more recently in Haiti, Ivory Coast, Nigeria and India.
Brazilian drug lords are also known to have 'necklaced' their enemies, most notoriously the journalist Tim Lopes in 2002.
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