China refused Tuesday to disclose why an Australian journalist working as an anchor for state TV has been detained for at least two weeks without charge.

Cheng Lei, an anchor for CGTN, China’s English-language state broadcaster, has been held since at least August 14 but Australian diplomats say Beijing has given no reason for her detention.

Her case is the latest to fray relations between the two countries which have withered over trade, security concerns about Chinese tech and Canberra’s push for a probe into the origins of the coronavirus pandemic.