The report said Malaysian Chung, who was 28, rode briefly at the Singapore Turf Club (STC) earlier this year.
The news portal said the STC had expressed its deepest condolences to the bereaved family yesterday.
Chung, who won 30 races, including the Malaysian Group 1 Selangor Gold Cup last year, had relocated to Singapore in January and was indentured to Singaporean trainer Leslie Khoo, said the report.
“It’s so senseless and to lose his son and his mother … makes it even more senseless. WT (Wah Thong) was a quiet boy and he worked hard at the stables,” Khoo was quoted as saying.
Besides Chung, three of his family members were also shot dead at a chicken processing factory in Batu Maung, Penang, early Wednesday.
The victims have been identified as Toh Hock Choon, 50, his common law wife Tan Saw Sim, 55, and Chung’s two-year-old son named Ah Bee.
Penang CID Chief Razaruddin Hussain had said that based on initial investigations, the act was committed by a close relative.