Meng Guanggang in his early years. Photo provided to China Daily

"I made a lot of money. We tried to benefit the justice system, and I still think (private investigation) is necessary."

He believes the new administration attaches great importance to the rule of law. And private investigators can be a good channel to prevent miscarriages of justice by helping the wrongly accused and convicted, and erroneously repudiated cases.

Meng believes some poor practices have tarnished the sector's image. But there's little that can be done without an industry association.

He handed his agency over to his nephew and moved to Beijing to support his son－the only surviving member of his immediate family－who studies in the capital.

Meng has published an autobiography and is working on a script. "I no longer deal with cases every day but still think about instituting the sector's legal status," he says.

"I even wrote to top leaders and got a reply. I'm hoping for the day my son can proudly introduce me as a private detective."

Han Junhong and Zhang Xiaomin contributed to this story.

By the numbers

1,000 private detective agencies are currently operating in China nationwide, experts say. There are no official statistics.

200,000 employed by the agencies. China's first private detective agency opened in 1993 with a team of just 10. Like private detective agencies nationwide, that first agency has grown too, now numbering 50 full-time and about 100 part-time investigators.