A South African digital forensic expert on Friday rejected allegations that he interfered with or altered data extracted from the cellphone of businessman Vusimuzi “Cat” Matlala and his wife Tsakani Matlala, describing the claims as “unfounded and baseless.”

Ratlhogo Peter Calvin Rafadi made the denial during cross-examination at the 57th session of the special court in Juba, where he is testifying as the prosecution’s final witness in the trial of suspended First Vice President Dr. Riek Machar and seven co-accused.

The allegations of tampering surfaced in October 2015 during investigations linked to politically motivated killings in South Africa.

A witness identified as Witness C from the Political Killings Task Team testified that data from the Matlalas’ previous devices could not be downloaded due to technical failures, raising suspicions of possible interference.

During questioning by Machar’s defense lawyer Dr. Geri Raimondo Legge, Rafadi was asked whether there had been any breaches, complaints, or incidents that could affect the integrity of his laboratory work.

Rafadi dismissed the accusations, saying they were based on speculation.

“There are unfounded allegations suggesting that I could have tampered with the phone of the suspect so that it could not be downloaded,” he told the court.

He said Witness C had testified that he possessed the expertise to block access to phones but nevertheless concluded that Rafadi might have interfered with the devices.

“I wish to repeat these are unfounded allegations. As a seasoned digital forensic expert, I have worked closely with law enforcement,” Rafadi said, adding that his professional record includes appraisal letters from police units.

Rafadi, who owns a private forensic investigation firm, emphasized that the phones in question were never brought to his laboratory and were never in his possession.

He attributed technical difficulties to investigators who may not be properly trained in digital forensics attempting to access devices using incorrect tools.

Presiding Judge James Alala Deng adjourned the trial until Monday, March 9, 2026, to continue Rafadi’s cross-examination.

Machar, 73, remains under house arrest, while his co-accused are detained at National Security Service facilities in Juba.

They face charges of murder, conspiracy, terrorism, treason, destruction of public property, and crimes against humanity.

Prosecutors allege SPLA-IO forces, allied with the White Army, killed 257 SSPDF soldiers—including commander Gen. David Majur Dak—and destroyed or seized equipment worth approximately $58 million during the March 2025 Nasir garrison attack.