The Taoyuan District Prosecutors Office investigated corruption at the Guishan Township Office and found that Yang Yongchang, an incarcerated public works section employee, was suspected of conducting fraudulent project inspections. Among them, a hiking trail project worth NT$2.9 million, tendered three years ago, required the construction of seven pavilions. Investigators found visible discrepancies between the actual structures and design blueprints just by visual inspection. In addition to interrogating Yang Yongchang, the prosecutors also summoned three others. After questioning, Kuan Yu-ling, a technical specialist from the public works section, was released on NT$100,000 bail; contractors Chan Chia-long and Li Chao-lang were released on NT$80,000 and NT$30,000 bail respectively, while Yang Yongchang was remanded in custody.
The prosecutors office stated that the Guishan Township Office tendered a hiking trail project worth NT$2.9 million in April 2009, which required the construction of seven pavilions. The project was awarded to Yufa Civil Engineering Co. and was inspected and accepted in January 2010, after which the contractor received payment without issue.
While investigating bribery allegations against township chief Chen Chih-mou, Prosecutor Lin Hsiu-min received a tip-off and directed investigators from the Taoyuan County Investigation Bureau to interrogate Yang Yongchang, the public works section employee responsible for supervising the construction at the time. They also summoned Kuan Yu-ling, the technical specialist from the public works section who was in charge of the inspection, and Li Chao-lang, the contractor from the winning bidder Yufa Company. Further investigation revealed that although Yufa had won the bid on the surface, it was actually Shin Li Enterprise that secured the contract under Yufa’s name. As a result, Shin Li's boss, Chan Chia-long, was also summoned for questioning.
Investigators conducted an on-site inspection of the pavilions along hiking trails in Guishan Township's Fuyuan Mountain, Dadong Mountain, Hill 405, and Xinchao Ridge, and found the structures to be significantly downsized—discrepancies with the design blueprints were obvious even to the naked eye. All four individuals denied cutting corners or conducting dishonest inspections. After questioning, they were released on bail ranging from NT$30,000 to NT$100,000, while Yang Yongchang was remanded in custody.