The Supreme People's Procuratorate (SPP) has pledged greater efforts to spot and correct improper commutation of sentences for "the rich and the powerful."

"Supervision will be tightened on sentence reduction, parole and serving time outside jail, with a focus on sentence alterations for the rich and the powerful," said an SPP document made public Wednesday.

"Suspicious commutation and early release, bullying, the unnatural death of detainees and escapes are major law enforcement issues people are concerned about. They demand justice in criminal penalties," said Shen Guojun, a senior SPP official.

There were more than 88,800 cases where criminals were put on probation, served their sentence outside of prison or had jail terms reduced improperly were rectified between 2010 and August this year.

Prosecutors were urged to see to that sentences, both imprisonment and fines, are fully carried out in a timely fashion, according to the document, a key instruction to prosecutors.

Supervision will target courts, police, prisons, detention centers, community corrective institutions and other places involved in criminal sentences.

According to the document, law enforcement personnel are banned from fabricating legal documents, bullying convicts and their relatives, refusing their legal rights or accepting money and gifts from them.

Prosecutors who ignore or cover up misconduct in sentence implementation or who abuse their power to influence commutation outcomes will be criminally pursued and their superiors will also be punished, it added.