The three fires at the Pretoria Magistrate's Court last month were all caused by arson, Chief Magistrate Desmond Nair said in a report on Thursday.

"I can confirm that arson was the cause of all three fires that disrupted court procedures in October," Nair told Beeld newspaper.

The conclusion was drawn following the completion of a forensic investigation.

The last fire was in the same court where ex-Ekurhuleni metro police chief Robert McBride's drunken driving trial was heard.