800 inmates sent back to jail in 2014

If inmates are diagnosed with serious illnesses, such as cancer, heart disease or high blood pressure, and are thus considered unable to serve their terms in prison, they can serve the sentences outside to receive medical treatment.

After initial investigations, prison departments submit documents of inmates who make such applications to local superior courts for new judgments. After the courts issue the new rulings, the commutation of sentences or conditional release can take effect.

In January, the CPC Political and Judiciary Commission issued a notice to stipulate strict regulation of the commutation of sentences, conditional releases and sentences served out of prison.

In March, the top prosecuting department launched a nine-month special action to target illegal behavior involved in such releases. The action was taken to fight judicial corruption, especially among senior officials, the wealthy and law enforcement officials, to improve judicial fairness and credibility, according to the SPP.

Yuan said prosecutors will pay attention to investigating prisoners, including corrupt officials, those who committed major economic crimes, Mafia-like gang members, and those involved in violent or terrorist attacks.

Zhou Guangquan, a law professor at Tsinghua University, said, "Some loopholes exist in the operation of commutation of sentences and releases on parole for the judicial authority.

"When holding hearings in such cases, the courts should invite the public and media to participate and supervise the entire trial processes, and the courts should also make the verdicts public online to improve transparency," he said.