CHANGSHA - A restaurant in China's Hunan province allegedly sent a gang to beat up a couple, after they posted an unfavourable online review about its food.

The brutal attack left the man in a coma, while his wife suffered broken bones, reported the South China Morning Post via Changsha Television.

The wife, surnamed Yu, had ordered barbecue chicken and beef from the restaurant last Tuesday (Sept 12) through an online food delivery platform for her friends, who were over at her place for a mahjong session.

However, she was not satisfied with the food and left a scathing review on the platform the next day.

"Expensive, not properly packed and not fresh," she wrote. "The portion size was average. I have never had barbecue meat that tasted so bad."

According to Ms Yu, seven men brandishing sticks and holding her delivery order arrived at the couple's place that same evening.

Her husband attempted to intervene when the men started to pull her clothes.

In the ensuing fight, he suffered brain injuries and was admitted in the intensive care unit of a local hospital. He is currently in a stable condition.

The men escaped before police arrived.

Police subsequently interrogated the restaurant owner, who confessed to sending the attackers as he was angry that the negative review would affect its rating.

No arrests have been made and the case is still under investigation, the report said.