A deputy police chief of a city that held a mass public display where 51 suspects were controversially bound together in a public square and some sentenced has reportedly said the action was "inappropriate" but was surprised by the wave of criticism, Dahe Paper reported on Thursday.

Bound with their names on signs around their necks, 10 of the 51 suspects in Xiangcheng, Henan province were instantly found guilty with 41 others awaiting sentencing.

A picture shows all 51 criminal suspects tied-up in public in Xiangcheng, Henan on March 31, 2012.[Photo/dahe.cn]

The move sparked a wave of criticism online with some dubbing it "X-Factor" justice, while others suggested it was a good way to deter criminals.

"The intention of cracking down on crime may be good, but the practice is inappropriate," an unnamed deputy director of the local Public Security Bureau was reported to have said. He added: "but I didn't expect it could draw such a criticism."

Yan Bin, a lawyer from Yandongfang layer office in Henan, told the paper the practice has violated China's Criminal Law as regard to "no one is guilty until people's court verdicts."