Chinese billionaire Long Liyuan died after dining on slow-boiled cat meat stew laced with the toxic herb Gelsemium elegans during a business lunch in the Guangdong province.

The case became an online sensation after the police said they had detained the local official, Huang Guang, who had also been hospitalized with food poisoning after the Dec. 23 lunch, in the city of Yangjiang.

The police now suspect that Mr. Huang slipped Gelsemium elegans into the stew while eating lunch with Long Liyuan, 49, who ran a forestry company, and another friend. To avoid suspicion, Mr. Huang apparently ate some of the stew himself. All three men were hospitalized, according to the police account, and Mr. Long died almost immediately.

The police discovered evidence that Mr. Huang had embezzled money from Mr. Long, and detained him on Dec. 30.