China detains US scientist who studied North Korea nuclear tests

The family of Chen Youlin, a scientist known for his research into North Korea's nuclear tests, says he has been wrongfully detained in China for nearly two years on spying charges. The family maintains the accusations are baseless and that Chen was simply continuing his academic work.

The case adds a new dimension to the already tense relationship between Beijing and Washington. In recent years, both countries have seen a string of cases involving citizens detained on espionage-related charges.

Chen's family is calling on Chinese authorities for transparency and a fair trial, while also urging US officials to get involved in the case. Observers say cases like this one can also chill scientific and academic exchange between the two countries.