This research-in-progress paper explores the potential external interference in academic freedom. Due to its large scientific output, China is taken as a case study. In some fields such as Taiwan, Tiananmen and Tibet, it is assumed that the academic freedom in regard to teaching, doing research and publishing is restricted. As yet, no study has assessed academic freedom with bibliometric data alone. This study aims to fill this gap, by proposing a bibliometric approach that indicates in how far Chinese publications differ from international publications in regard to the co-occurrence of terms related to contested topics. The three topics tested in this proof-of-concept study are Tiananmen, Tibet, and Uyghur. Results show that papers exclusively published by Chinese scientists on these topics lack terms that can be conceived as sensitive, whereas other nations than China use sensitive terms. The findings suggest that the bibliometric method is capable of indicating potential external interference in academic freedom to some degree. However, it cannot distinguish between censorship and self-censorship or genuine lack of national interest in a topic. Future research will focus on the automatic extraction of censored or restricted research topics based on bibliometric data.