BEIJING - China's top prosecuting body on Tuesday announced new measures to stem judicial corruption in granting parole or commutation of prison terms.

Under the regulation released by the Supreme People's Procuratorate, prosecutors will launch "full-scale investigation and verification" over a criminal's qualifications if their sentence is reduced by a significant margin or they are placed on long-term parole.

Prosecutors will especially target those found guilty of corruption, mafia-style or terrorist crimes, among other serious criminal offences. People who committed serious economic crimes such as fraud, or other crimes with "severe social impacts" are also subject to the examination.

The authorities hope the move will strengthen prosecutors' supervision over rich and powerful people attempting to use their connections or bribery to have their penalties mitigated.

Prosecutors will also focus on suspicious sentence commutations. They will check carefully if a prisoner only serves a short prison term before getting a commutation, or if they are given frequent commutations or parole.

In China, criminals can have their prison terms shortened if they show an attitude of obedience or repentance in prison, or "made important contributions." Such contributions include stopping others from committing serious crimes, reporting others' criminal activities, saving other people's lives, coming up with new inventions, or outstanding performance in disaster relief operations or accidents.

Applications to commute a prisoner's sentence are submitted by prisons or law-enforcement bodies and have to be approved by courts.

To prevent judicial corruption in granting sentence commutations, prosecutors will have more involvement in the process of drafting the reports and court rulings, according to the regulation.