China has jailed a man who was pushing for compensation following a tainted milk scandal.

Zhao Lianhai's child was one of 300,000 in China who became sick after drinking poisoned milk in 2008.

The dangerous chemical melamine was added to milk formula to artificially boost protein levels.

Six children were killed and another 50,000 hospitalised.

This turned Zhao Lianhua into an activist. He set up a website to help victims and push for compensation.

Police arrested Zhao last December, charging him with the crime of picking quarrels and provoking trouble.

He has now been found guilty of "inciting social disorder" and given a two-and-half year jail term.

Zhao's wife Li Xuemei says the family will appeal against the decision.

"Of course we cannot accept this. We will appeal. This is something we have to do," she said.

Amnesty International has condemned the sentence.

"We are appalled the authorities have imprisoned a man the Chinese public rightly view as a protector of children, not a criminal," Amnesty spokeswoman Catherine Baber said.

"Zhao Lianhai should never have been arrested for organising a self-help group and exercising his legal rights to seek compensation from a commercial firm."

After an initial cover-up during the Olympic Games in Beijing, China jailed or executed a handful of farmers, milk dealers and executives at Sanlu, the dairy firm that sold the tainted milk, but never announced the sentences for government officials detained after the scandal.

Farmers and dealers had put melamine, an ingredient in plastics and fertiliser, in poor quality milk so it would show higher protein levels in tests.

Sanlu executives said they reported the problem to the government in August 2008, but China took no public action until September when Sanlu's partner, dairy cooperative Fonterra, took the matter up with the New Zealand government.

China set up a compensation fund for children whose health had been seriously damaged, but the children of many of the parents who allied with Zhao were not eligible for compensation.

- ABC/Reuters