The arson accused, who confessed to igniting the fire that killed 76 people and injured 86 others at the Usindiso building in Marshalltown, Johannesburg, in 2023, has been detained in a secret location - for his own safety.

Sithembiso Lawrence Mdlalose's lawyer, Dumisani Mabunda, said his client's life was in danger following his damning confessions.

Mdlalose was arrested after making an initial confession on Tuesday before a commission of inquiry.

He then made a second confession in the Johannesburg Magistrate's Court on Wednesday.

On Tuesday, Mdlalose told the commission he had set the fire to conceal a murder, but the blaze grew out of control on 31 August 2023.

He said he had severely assaulted a man and then choked him to death.

Mdlalose said he then poured petrol on the man and threw a burning matchstick onto him. The fire spread from the room, which he identified as a "slaughterhouse", to other parts of the building, burning 76 people to death.

Eighty-six other people sustained injuries attempting to escape the inferno.

Speaking outside the court on Wednesday, Mabunda and NPA regional spokesperson Phindi Mjonondwane confirmed that Mdlalose had confessed in court on Wednesday - a day after he was arrested.

Mabunda said he was in possession of Mdlalose's confession.

"What is of paramount importance is the safety of my client. There is an arrangement between the NPA, police and us that my client will be detained in a private cell. I cannot reveal where he will be detained, for his safety," said Mabunda.

"Many lives were lost on that day. There is a public outcry. Many are aggrieved. There is also a drug lord that is alleged to be involved. Therefore, Mdlalose's safety is at risk and important to us," he added.

"My client cooperated fully with the police after his arrest. However, every accused person is innocent until proven otherwise. We must also consult further. This matter is fairly new, and investigations might take a long time. Many people are alleged to be involved in this matter."

Mdlalose's arrest on Tuesday afternoon came after he detailed shocking testimony before the commission of inquiry into the fire.

He told the commission that, under the instructions of his drug lord, he had killed a person.

Mdlalose said the deceased was brought to him by "his Tanzanian drug lord" to be assaulted.

He said the man's head was covered with a sack.

After assaulting the man, Mdlalose said he removed the sack and realised that he knew the victim.

He then choked the victim to death.

After that, he went to a nearby filling station, bought petrol, returned to the room, poured petrol over the deceased, and threw a burning matchstick onto him.

The fire then spread to various parts of the building, killing occupants and injuring others.

He claimed dead bodies had been hidden in the building before the 31 August incident.

He alleged that many people had been killed at the Usindiso building.

Immediately after his testimony on Tuesday, Mdlalose was taken away by the investigating officer.

When contacted for comment about allegations of other bodies in the building, Gauteng police spokesperson Colonel Dimakatso Nevhuhulwi said: "We are no longer commenting on this matter."

On Tuesday, Nevhuhulwi issued a statement confirming Mdlalose's arrest. 

On Thursday, the magistrate, Ulanda Labuschagne, charged Mdlalose with 76 counts of murder, 86 of attempted murder and one count of arson.

Mdlalose is expected back in the Johannesburg Magistrate's Court on 1 February.