In The Case of the Haunted Island, Ah Song was Chinese merchant who ran the general store on the remote Pacific atoll of Oto-Via. When the native island population decided to evacuate the island after Captain Nathaniel Clark had convinced them that it was haunted, Ah Song left along with them. He went first to the Paumotus, where Captain Clark had brought the islanders, and then later moved to Atuona. When Biggles and Marcel caught up with him, he was minding a store for another Chinese owner who was away in Tahiti on business.
Ah Song was at first unwilling to talk about events at Oto-Via until Marcel reminded him that he might find himself accused of complicity in murder. After that, Ah Song gave Biggles and Marcel a highly detailed account of what happened: how the Belinda had been thrown onto over the reef onto the atoll by a hurricane, how the mostly drunk Captain David MacDonald had kept the islanders away from the ship, giving rise to talk of a "mad Englishman". Ah Song went on to describe how the Mahina had arrived with Captain Clark. One night, after hearing a noise, an islander had rowed across to the Belinda and saw the crew of the Mahina transfering heavy loads from the Belinda to their own ship. After that, Clark had told the islanders that MacDonald had killed himself and that his ghost would haunt the island. He offered to take the islanders off the island. Ah Song thought that Clark might kill him or the other islanders if they talked. He was, according to Ah Song, a savage man. Ah Song added that there was a glut of canned salmon, corned beef, rice and beans among the islands, causing prices to fall. He claimed he did not know where these goods came from, although Biggles pointed out that it was obvious they were the cargo from the Belinda which Clark had stolen.
Biggles met Ah Song a second time, and not too long after. In Biggles on Mystery Island, Biggles was once again sent to investigate strange goings-on in the Pacific, this time involving disappearances of ships and people visiting the British possession of Oratovoa. On the way there, he stopped at Atuona where he called on Ah Song. No details are given about this second meeting but presumably Biggles would have asked Ah Song for any information he might have picked up about Oratovoa.