BEIJING, Feb. 24 -- Chinese authorities have vowed to crack down on judicial corruption in commutations of sentences and probation following a number of cases of convicts bribing their way out of jail.

"Terms and procedures on commutation, parole and serving a sentence outside jail for medical reasons should be stringent within the framework of the law," said an instructive document released on Monday by the Commission for Political and Legal Affairs of the Communist Party of China Central Committee.

In one high-profile case, Zhang Hai, former board chairman of Jianlibao Group Co. Ltd., a Chinese beverage giant, used illegal means to have his sentence cut by five years in a second court trial and had his jail term further reduced by more than four years while he was serving the sentence.

In a Monday statement, the Supreme People's Procuratorate (SPP) revealed that Zhang's lighter sentence was achieved through stealing crucial information revealed by other suspects to serve as his own contributions to police investigations.

He also persuaded outside connections and bribed prison and justice officials to fabricate documents on his good behavior to claim two commutations.

While confirming the valid role of remission in rehabilitating convicts and helping them return to society, the commission noted "some problems" in this area that "severely trample the sanctity of law and harm the credibility of law enforcement," citing criminals who use money and power to dodge punishment.

According to the commission, illegally making decisions to commute a sentence or grant release on probation will be severely punished.

The document focuses on regulating commutation, parole and serving a sentence outside jail for medical reasons for three kinds of crimes, namely taking advantage of one's position, disrupting financial order and financial fraud, and organizing mafia-style groups.

In order to warrant remission, criminals convicted of these three crimes should be proactive in disgorging ill-gotten gains, assisting in recovering illicit money and goods overseas or paying compensation, it said.

Those who try to reduce their sentences or secure probation using personal influence or other improper means will be refused remission even if they are repentant, according to the document.

Criminals convicted of the three crimes should be prevented from applying for commutation for a period, while those sentenced to life in jail should not be eligible for remission until they have served three years, it said.

Once the life-termer is granted commutation, they should be refused further remission within two years and each abatement of sentences should not be over one year, it added.

According to the document, convicts with diseases are not allowed to serve their sentences outside jail if they do not cooperate with medical treatment arranged by penalty enforcement organs or they are likely to present a danger to society outside jail.

The commission called for procedures on commutation, parole and serving a sentence outside jail to be made public in order to prevent judicial corruption.

Under the current law, requests for a convict's remission should be proposed by jails, detention houses or other penalty enforcement organs, and then submitted to the courts, with procuratorates supervising the whole procedure.

Submissions of commutation, probation and serving a sentence outside jail should be made public and subsequent verdicts by the courts must be published on their official websites, the document noted.

Hearings are needed when it comes to remission for convicted officials above county level involved in job-related crimes, and criminals convicted of death sentences with a reprieve or life sentence for disrupting financial order or financial fraud, it said.

Publicizing submissions and verdicts in warranting remission will effectively curb judicial corruption concerning commutation and probation, said Zhou Guangquan, law professor of Tsinghua University.

To curb abuse of power in warranting remission, law enforcement officers will have sign-off and be held responsible for each procedure they handle, said the document, adding regular supervision and inspection will be conducted nationwide.

Judicial officers will be sacked if they are found illegally commuting a sentence or granting release on probation, through means such as fabricating information, forging materials or taking bribes from convict.

"Trading power for money or dereliction of duty will be severely punished," the commission said.

Apart from judicial officers, people who provide fake medical certificates to help criminals escape penalties will be held accountable, it added.

According to the SPP, 24 people are being or have been investigated for suspected involvement in Zhang's manipulations. They include 11 in the judiciary and prison service, three working in detention centers, one court official, two lawyers and seven others.

Among them, three working in the prison, court and detention services have already been sentenced to five to six years in jail, with Zhang's secretary, Kang Jie, receiving 11 months.

Meanwhile, the two reduced sentence decisions have been revoked and the second court ruling is also being reconsidered by Guangdong's higher court.

Related departments are now trying to arrest and extradite Zhang and Huang Lu, Zhang's girlfriend who is alleged to have bribed officials for a reduction in his sentence. Their whereabouts were not revealed by the SPP.