In Biggles and the Blue Moon, Chin Tusang was a Chinese ex-employee of Lin Seng who was conscripted as an Indonesian commando and sent to infiltrate Malaysia during the events in the book. Chin was originally a pearl buyer for Lin Seng but left his service to work for a Japanese company in Indonesia. Later, he had been conscripted and trained as a commando. Since he knew Malaysia and the Taihan region well, he was sent to infiltrate the northeast coast of Malaysia as part of a party of 50 commandoes. Their objective was to reach Taihan and seize control of Lin Seng's pearl collection.
Once his unit was near Taihan, Chin deserted and made his way to Taihan in order to warn Lin Seng about the approach of the commandoes. Lin Seng thought he did this out of a genuine love for pearls, although Biggles was more inclined to take a cynical view that perhaps Chin only wanted to get his old job back. Nonetheless, Lin Seng decided Chin could remain at Taihan, although under strict guard at all times.
Later, after Biggles had landed at Taihan in his Auster, Algy went in search of Lin Seng to bring him to the landing ground. He found Lin Seng unconscious under a patch of trees with Chin standing over him, about to stab him with a knife. Algy fired a running shot which missed but it was enough to stop Chin's attempt at murder and send him bolting. Algy gave chase and finally shot him, recovering from Chin an attache case which, as it turned out, contained Lin Seng's pearls.