To raise money for his ill son, Xia Jun advertises himself as a "human punch bag" outside a subway station, charging 10 yuan (US$1.6) for per punch.

A desperate father who went viral online last year for becoming a "human punch bag" to raise money for his sick son failed to save the child, the Legal Evening News reported.

The three-year-old boy, who was suffering from leukemia, had only one month to live according to a hospital in Beijing.

Xia Jun's son was diagnosed with acute myeloid leukemia in 2013. Last year, Xia took him to Beijing for treatment. To cover the high medical costs, he stood outside a subway station advertising himself as a "human punch bag," charging 10 yuan (US$1.6) for per punch.

He successfully raised 800,000 yuan (US$ 128,960) from the public.

Yet the boy's disease suddenly deteriorated earlier this year, and he stopped responding to any treatment after undergoing chemotherapy for a long period.

Xia decided to take his son back to their hometown in southwest China's Sichuan Province. "I should have spent more time with him," Xia said. After going home, he planned to take the boy anywhere he wanted to go and buy him all toys he desired.

"I can't return to society right now, but I won't forget the help people gave us," Xia said.