“I am not satisfied that sufficient grounds exist that Mr X is not a competent witness,” Judge Ian Farlam said in Pretoria.
Farlam said he had observed the witness and was satisfied he was competent.
Earlier, Dali Mpofu SC, for wounded and arrested Marikana mineworkers, asked for Mr X to undergo mental observation. He may not be named to protect his identity.
“The nature and purpose of this application is simply to seek a ruling that Mr X’s competence and capability to give evidence as a witness in the commission be investigated, preferably by means of a medical inquiry into his mental or psychological state,” Mpofu said.
He said the rights of affected parties had to be protected.
“Mr X is a very important witness, and the issues he is pronouncing [on] are issues that are of a very serious nature. The allegations he makes in respect of certain people have far-reaching implications,” Mpofu said.
He said on Friday that Mr X said his physical or mental distress was caused by supernatural powers and actions against him.
Mr X’s face was revealed to the commission for the first time on Thursday, when he started giving evidence via video link from another location.
He testified that pieces of flesh were cut from one of two Lonmin security guards, Hassan Fundi and Frans Mabelani, strikers killed. The flesh was brought to a sangoma (traditional healer) to make muti. This was supposed to make the strikers bulletproof in their confrontation with police.
He testified about “the killing and intimidation of Lonmin employees who were unwilling to take part in the violent strike”.
The commission is investigating the deaths of 44 people during the violent wage-related strike at Lonmin’s platinum mining operations at Marikana, near Rustenburg, North West.
On August 16, 2012, 34 people, mostly mineworkers, were shot dead by police, who were allegedly trying to disarm and disperse them.
Ten people, including two policemen and the two security guards, were killed during the preceding week.