Beijing police have detained a man and a woman over a mercury poisoning case wrongly blamed on a can of Sprite last year.

Investigations showed Liu Xiaojing, 28, had secretly added mercury to a can of Sprite while having a meal with Ma Sai in a restaurant in Xicheng District, on Nov. 7, 2009, Beijing Municipal Public Security Bureau said in a press release Monday.

Ma, 21, sipped the drink and vomited mercury beads. He said he felt sick and was immediately rushed to hospital. An examination confirmed that he was poisoned by mercury.

The press release said Ma acknowledged that Liu had intentionally put the toxic chemical into the soft drink after he called police, but still collaborated with Liu to keep the poisoning secret.

Police are still questioning the pair, both natives of Beijing.

An unnamed police officer said Liu, a mother of a young girl, had an secret affair with Ma and a dispute might have prompted her to poison him.

Two months after the case, a 13-year-old Beijing student also claimed he was poisoned after drinking Sprite.

Police were investigating the case after receiving the report by the boy's parents on Jan. 17.

Coca Cola, producer of Sprite, said in January that the company had a stringent quality management system, and its products were safe and in line with China's food and drink safety standards.

(Xinhua News Agency March 16, 2010)