The mother of Hugjiltu holds the photo of his dead son. [Photo/CFP]

Proving an executed man innocent was the first since the founding of the People’s Republic in 1949.

He said Hugjiltu's case shows the determination of the leadership to promote the rule of law.

Justice didn't come as soon as Tang expected in 2005 when he handed the first report to the central leadership. The case didn't return to court for years.

"I continued my work because other people who believed in justice encouraged me," Tang said.

Shang Aiyun, Hugjiltu's mother, said: "I could see a sense of justice in Tang when I first met him. His words brought me a feeling of warmth.

"Tang has done tremendous work for my family, but he refused to accept a dinner or even a cup of tea from us. He said it is his duty".

Having reported on political and legal affairs for more than 30 years, Tang has covered numerous stories with the Hugjiltu case just one of them.

Although he is going to retire in two years, he maintains his passion for pursuing truth and justice for ordinary people.