Chinese netizens have launched a firestorm of criticism after a former official jailed for bribery got years cut off his sentence for writing books behind bars.

Prison authorities in central Hubei Province said Monday that Zhang Erjiang, ex-secretary of the Tianmen City Committee of the Communist Party of China, had been given a three-and-a-half year reduction in his 15-year term.

The decision reflected Zhang's "good behavior in rehabilitating himself by writing and publishing four books in prison," according to an announcement released by the Hubei Provincial Bureau of Prison Management.

Zhang, a graduate of Wuhan University who majored in history, completed four books on China's classical literature after he was jailed in 2002.

In the preface of one book, Zhang said he wrote in prison because he wanted to "explore the real features of Chinese culture and enhance the confidence of the Chinese people."

But a flood of criticism and doubts appeared on the Internet after the move was announced, with critics taking aim at the quality of his books and the legal validity of the sentence reduction.

"A book written by a corrupt official is destined to be corrupt," said an anonymous comment.

According to China's law, every prisoner, except those who are deprived of their political rights, can write books in prison. But only those who have shown true repentance or outstanding behavior could have their sentences reduced.

"Personally, I do not think writing and publishing books can be counted as 'outstanding' behavior in prison," said Zhao Bingzhi, secretary-general of the Beijing-based China Law Science Society Criminal Law Research Institute.

"Authorities making such decisions should be cautious," he warned.

Hubei prison authorities remained silent. One official, who asked not to be identified, declined to comment since "any comments on Zhang are now sensitive."

Several other jailed officials have written books while behind bars. But Zhang is the only one who received a sentence reduction.

In 2008, Qiu Xiaohua, former chief of the National Bureau of Statistics, published a best-selling book on China's economy.

(Xinhua News Agency June 12, 2009)