Taiwan's Investigation Bureau says China is now hunting critics beyond its own borders, a worrying sign for foreign researchers and reporters working on Chinese espionage.

• German scholar Jürgen Kremb was tailed by a Chinese woman while on a trip to Alishan in Taiwan.
• Kremb, a former Beijing correspondent now studying China's spy agencies, spotted her by her northern Chinese accent and behavior.
• Security footage backed up his account, and the woman left Taiwan two days after the investigation started.
• The bureau says China is targeting not just Chinese and Taiwanese people but anyone who speaks up for democracy and human rights.

Outlook: Taiwan plans to work more closely with other democracies to push back, while cases like this are likely to keep surfacing.