The man who blew the whistle on milk contamination in China has been killed, but the circumstances of his death are shrouded in mystery.
Jiang Weisuo, 44, started to expose how milk was being contaminated in 2006, two years before the scandal that enveloped Sanlu, then a subsidiary of New Zealand dairy giant Fonterra.
Jiang, the general manager of dairy products plant in Shaanxi province, died on November 12, 10 days after suffering two knife wounds, the Xian Evening News reported.
The newspaper cited an unidentified local police source who said Jiang had been stabbed by his wife during a family dispute. Police had detained his wife as a suspect and were waiting for autopsy results to confirm if the wounds were lethal.
But on Friday, the Beijing News, citing an anonymous source, said Jiang's wife did not stab her husband. ''Several people were present and it was unclear who did it,'' the source said. "It probably had to do with monetary matters."
The South China Morning Post said Jiang's prominence as a food safety critic has caused some media outlets to question whether his death was related to his efforts to clean up the industry. Reports have speculated he was attacked after rejecting a blackmailing threat or targeted by a hit-man.
However, Xinhua news agency reported at the weekend that Jiang was killed during a dispute with his wife over his drinking habits, quoting an officer from the Xian Municipal Public Security Bureau in Shaanxi Province.
He later died in hospital, the police officer said.
Six of the nine suspects involved in Jiang's death, including his wife Yang Ping and her younger sister Yang Caiying, were detained over alleged assault, police said.
Yang Ping had confessed to the crime, according to police.
Jiang had faced great pressure after his whistleblowing in 2006.
He was called "black sheep" by his competitors in the dairy industry.
It was not till 2008, when the milk powder contamination scandal shocked the whole country, that Jiang earned himself the reputation of ''hero'' and ''pioneer'', Xinhua reported.
The melamine-tainted milk power resulted in the death of at least six babies and left 300,000 others ill in the country in 2008.
A number of Chinese officials were removed from their posts and scandal-tainted Sanlu Group, once a leading dairy producer in the country, went bankrupt following the exposure.
Some members of Sanlu's management were jailed.
Fonterra, which had four members on the Sanlu board, repeatedly said it had no knowledge of the contamination before August 2, 2008. It said when it was notified, it advised
Sanlu the only acceptable level of contamination was zero.
The scandal cost Fonterra all of its approximate $200 million investment in Sanlu.
- Fairfax Media