The son of a fruit vendor who died in a confrontation with four urban management officers said he will appeal their sentences as he believed they were too light.

"The verdict is unfair with too light a sentence," Deng Qingqiang, son of Deng Zhengjia, a watermelon vendor in Linwu county, Hunan Province, told the Global Times on Sunday.

Liao Weichang and Yuan Cheng received 11 and six years respectively for their roles, while accomplices Luo Weiping and Xia Jiyu were sentenced to four years and three years and six months for intentional injury, according to a statement released by the Yongxing County People's Court official news portal on Friday.

Deng, 56, fell to the ground and died on July 17 after he and his wife argued with four officers about selling watermelons on the street without a permit in Linwu county. 

The court alleged Deng's wife insulted the officers and Deng himself poked Liao during the altercation, provoking the beating and Deng's eventual death from a ruptured blood vessel in the brain.

The autopsy released by Linwu county on its official website in August showed Deng, who had vascular malformations of the brain, died from head injuries caused by an external force, but did not reveal the exact cause of the external force.

Relatives of Deng questioned the autopsy and want to appeal the verdict. Deng said his father had been in good health and never told them he had anything wrong with his brain.

"The four officers, public servants for the country, should be severely punished for my father's death," Deng said.

Mao Lixin, a lawyer with the Shangquan Law Firm, told the Global Times the penalty was "reasonable."

According to the Criminal Law, a suspect charged with intentional injury and causing a person's death faces a sentence of less than 10 years.

In this case, the direct cause of Deng's death was his potential brain lesions and not just the beating, and so it was reasonable for the court to issue a lighter penalty while the principal criminal received 11 years, Mao argued.