Taiwan's biggest ongoing political fraud case has been thrown into doubt after its main defendant cut off his electronic monitor and vanished, a setback for prosecutors and a blow to public trust in the courts.

• Chang Chun-chieh, a former aide to independent lawmaker Kao Chin Su-mei, is on the run after his tracking bracelet was found broken in a Taipei park.
• He is accused alongside Kao of faking staff hires to pocket public money, and separately of taking government and state-company grants for events that never happened.
• Prosecutors treat him as more deeply involved than the lawmaker herself, since he is tied to all four parts of the case.
• The timing and location of his escape point to careful planning, and his eldest daughter, also charged, is already in China.
• With 22 defendants and a schedule built around questioning him as a witness, his disappearance could stall the whole trial.

Outlook: Police are hunting him under an arrest warrant, but if he has already left for China the case against the remaining defendants could drag on for years.