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

The finding that an executed man was innocent was the first of its kind since the foundation of the People's Republic of China in 1949.

The hard-won reversal of the verdict is regarded as historic in China's judicial development. Tang said the case shows the determination of the current leadership to promote the rule of law.

He admitted that the difficulties he faced during the lengthy retrial process exceeded his expectations.

"When I handed in the first report to the central leadership in November 2005 through Xinhua News Agency's special circulation of news reports on sensitive issues, which was read by the top Chinese leadership, I thought justice would come soon," he said.

However, the complexity of the evidence and reluctance of the judicial authority in the region to admit it had done anything wrong meant that years passed without the case returning to court.

"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".

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

He is due to retire in two years, but until will continue to pursue truth and justice for ordinary people.