Wu Fang, 28, is alleged to have added a highly toxic chemical called thallium sulfate to her neighbours' table salt in April over a real estate feud, the official Xinhua news agency quoted local police as saying.

Ms Wang Shunai died in Laiwu city in Shandong province on May 7 and her husband passed away a few days later, according to Xinhua.

Around 90 people attended Ms Wang's funeral and had lunch at the victims' house, where they also consumed the poisoned salt.

Eighty-two fell sick, of which 22 were hospitalised, Xinhua said.

Police have since detained Wu and the person who sold her the thallium sulfate, which is colourless, odorless and tasteless. -- AFP