Bodies were found in the tavern in the city of East London on June 26, without any apparent clues to the cause. The police are still investigating the incident.
"We can’t say whether they have ingested it or whether it was a by-product of a chemical that they have taken," Matiwane told a media briefing, as quoted by local news website Eyewitness News.
He said experts have yet to establish if methanol intake was the direct cause of deaths in the East London tavern, but added that lab results have already ruled out stampede and alcohol overdose.
The owner and two workers of the Enyobeni Tavern were detained by the police for selling alcoholic beverages to minors two weeks prior to the incident. They were later released on bail.