China has opened a probe into Puma Shen, a prominent Taiwanese lawmaker it has previously sanctioned, for alleged criminal "separatist activities", authorities said Tuesday.

Shen is an outspoken member of the ruling Democratic Progressive Party (DPP), which advocates for Taiwan's sovereignty.

That has previously brought him into the crosshairs of Beijing, which considers Taiwan part of its own territory and has not ruled out using force to bring the self-ruled democratic island under its control.

China imposed sanctions on Shen a year ago, barring him from entering mainland China or the special administrative regions of Macau and Hong Kong.

On Tuesday, the public security bureau of southwestern Chongqing said it had "decided to open a case for investigation" into Shen and will "pursue

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