In Biggles' Chinese Puzzle (short story), Ching Loo was a wealthy Chinese merchant who owned Ching Loo and Co., a large commercial concern with offices in every big Eastern city as well as Paris and Marseilles. Ching Loo also had a lot of property in Saigon, the setting for the short story, and more particularly, owned the Pagoda Palace Hotel, where Marcel, and later, Biggles and co. stayed.
Ching Loo himself was never seen in the story, preferring to remain at his country house most of the time, with most of the operations of his criminal enterprise managed by able lieutenants such as Estere. Towards the end of the story, Ginger caught sight of Estere speaking to a well-dressed Chinese man and some policemen or soldiers outside the entrance of the airport terminal. The Chinese man might have been Ching Loo but we are never told. Certainly Marcel's Morane, which the gang had seized for communications between Saigon and Ching Loo's country house had been drawn up in front of the terminal to await passengers.
We do not know what happened to Ching Loo at the end of the story. His criminal organisation had been destroyed and we suppose he must have suffered the same fate as that of Estere--a long prison sentence.