Judge Daniel Berger on Monday dismissed with costs an urgent application made by suspended Gauteng Health Department head Tiego Ephraim Selebano to set aside a subpoena to appear before the Life Esidimeni hearings.
Selebano's attorneys told Berger that they intended to appeal the ruling.
In his ruling, Berger said: "I have no doubt that the arbitrator considers Selebano's evidence as important for the hearings. As the head of health, it would be astonishing if he had no evidence to contribute to the arbitration."
Berger said the subpoena was issued properly. Selebano filed an application in the South Gauteng High Court in Johannesburg last month, challenging a subpoena requesting him to appear before the Life Esidimeni arbitration hearing on the deaths of more than 140 mentally-ill patients.
The court excused Selebano from appearing at the hearings until judgment was handed down.
The application was lodged against Gauteng Premier David Makhura and health MEC Gwen Ramokgopa, who issued the subpoena requesting Selebano to appear before Justice Dikgang Moseneke on December 4.
Selebano wanted the High Court in Johannesburg to set aside the subpoena and has claimed in court papers that he feared incriminating himself.