According to the Radio Times, the entire production was filmed in and around London including the scenes set in China.
From a factual documentary series about aviation incidents to this about a fictional one, here you might recognise the voice of the character John Tennant (antagonist of Madeline Delaney) who is played by Jonathan Aris because he has narrated well over two hundred episodes of Discovery's Air Crash Investigation (2003).
The writer and key Police Officer both hail from Hong Kong, in reality the actor playing office Hana Li was born in Shanghai, China.