Taiwan's top court sent a Chinese espionage case involving former Democratic Progressive Party (DPP) staffers back for retrial, in a setback for prosecutors.

• Four former DPP-linked aides were accused of passing government secrets to Chinese intelligence, including officials' travel schedules for the president and vice president.
• A lower appeals court had cut prison sentences for three of them and fully cleared the fourth, finding the leaked material was mostly public information, not real secrets.
• The Supreme Court tossed out both the convictions and the acquittal, saying the appeals court's fact-finding was flawed and ordered Taiwan's High Court to hear the case again.
• The case highlights ongoing concern in Taiwan over Chinese infiltration attempts targeting political staffers and government offices.

Outlook: The High Court will have to re-examine the evidence and issue new rulings on guilt and sentencing for all four defendants.