Official in Guangdong province is accused of lacing business lunch dish with toxic herb to murder billionaire Long Liyuan

The sudden death of a billionaire in southern China is causing police to ask: was it murder by cat meat?

Long Liyuan, 49, died on 23 December in wealthy Guangdong province after sharing a dish of slow-boiled cat meat stew, a southern delicacy, with two men over a business lunch.

One of the men, local official Huang Guang, was arrested by police on Friday on suspicion of poisoning the hotpot with a toxic herb. Police say Huang and Long had economic disputes.

Huang, deputy director of agriculture in Guangdong's Bajia township, is suspected of poisoning the hotpot with the herb Gelsemium elegans, according to a statement on the microblog of the investigating police. The poisonous plant is found in forests in parts of China.

All three men became sick but Long died because he consumed more of the herb, the statement said.

Long and Huang had met for lunch to discuss a business contract. Long, who ran a forestry company in Guangdong, wanted to lease a piece of woodland and develop it, the Nanfang Daily, the mouthpiece of the Guangdong Communist party, reported on Tuesday. They had eaten at the hotpot restaurant before but this time the cat meat dish tasted a little different, the report said.

The third man at the table, Huang Wen, a friend of Long's, was quoted by media as saying he had not eaten much because it tasted "more bitter" than usual.

Long, who ate more than the others, soon felt dizzy and sick and was taken to a hospital where he went into cardiac arrest and died, according to the Nanfang Daily.

Police initially detained the restaurant's owner on suspicion of serving unsanitary food. But the businessman's family refused to believe it was a simple case of food poisoning, pressed the police to investigate further and offered a reward of 100,000 yuan (£10,000) for information about his death.

Guangdong is known in China as a province where people eat exotic creatures, including snakes, insects and several feline species. Many people blamed the outbreak of the Sars virus in 2002 on the poor hygiene and biological mishmash of Guangdong market stalls, some of which offer civet cats for sale.

Long preferred meat from domestic cats, and often used to go the same restaurant to eat the dish. His family dismissed the possibility of natural or accidental causes of death.

"He went several times to eat cat meat in the past. On each occasion, the cat was freshly killed before being put in the pot. He never had any food poisoning problems before. It must have been murder," a relative was quoted as telling the local newspaper, Xinkuaibao.