Poisonous pork accounted for half of the poisoned food cases handled by courts across the Guangdong provincial capital in recent years.

Courts in the southern metropolis handled 87 poisonous pork cases between 2009 and last year, accounting for 50 percent of the total cases involving poisonous food, according to a statement from Guangzhou Intermediate People's Court.

Most of the defendants were brought to court after they were found to be feeding their pigs with Clenbuterol, also known as lean meat powder, and selling the pork knowing that it contained the chemical, the statement said.

Courts have also handled a number of cases involving feeding fish or other freshwater products with malachite green from 2009 to last year.

Malachite green, used as a pesticide and fungicide in fish and other freshwater produce, is a poisonous chemical that can cause cancer and deform human embryos.

In other cases, formalin, which contains formaldehyde, was used to soak frozen meats and aquatic products to keep them fresh, the statement said.

Courts in Guangzhou handled a total of 173 poisoned food cases and another 330 involving fake medicines in the six years up to 2014. But the figures are rising, the statement said.

Of the 864 defendants brought to trial, only 54, or 6.25 percent, were sentenced to serve a prison term of at least three years, with the highest reaching 15 years in prison.

And 522 people, or 60.42 percent, were sentenced to less than three years in prison, while 228, or 33.33 percent, were granted probation.

Sun Yuanming, dean of the College of Food Science at South China Agricultural University, said the growing number of cases was the result of the huge profits that can be made.

"The costs for producing counterfeits is very low. Relevant departments lack efficient supervision methods," Sun said.

Zhou Fengjian, a lawyer at Yingke Law Firm, said that to deter others from such practices, those who produce poisonous food and fake medicines should be seriously punished according to appropriate laws.

"According to Chinese law, the heaviest punishment is death when an action has caused death or injuries," Zhou said.

Zhai Jiajia contributed to this story.