China is increasingly targeting people outside its borders in a tactic known as transnational repression, which aims to stifle debate or criticism.

Steve Tsang, the director of the Soas China Institute, says Chinese student protesters in the UK have long been photographed and monitored, but the practice “may well” have increased with newer surveillance technology.

Students say their families in China have also been threatened by local authorities, warning them to stop engaging in political activities overseas.