A man who has served 17 years of a life sentence in prison for the murder of his wife has been acquitted and released.

The High People's Court of Anhui province overturned the conviction of 51-year-old Yu Yingsheng on Tuesday, more than 17 years after his wife Han Lu was killed at their home in December 1996.

Yu had been prosecuted by the People's Procuratorate of Bengbu and sentenced to life in prison by the Intermediate People's Court of Bengbu. The verdict was upheld by the provincial high court.

But the evidence was insufficient and contradictory, high court officials said on Wednesday.

The Tuesday ruling is one among a handful of reversals over the past several months.

On March 26, two men in Zhejiang province were acquitted of a 2004 rape after a retrial found insufficient evidence to support their convictions.

Zhang Hui had been serving a death sentence that was postponed for two years, while his uncle Zhang Gaoping was sentenced to 15 years in prison for the rape of a 17-year-old girl.

Last month, five men who had served 17 years in prison for the murders of two taxi drivers in Hangzhou, Zhejiang province, were acquitted after fingerprint evidence linked the crimes to a different man.

The High People's Court of Anhui said it decided to re-examine Yu Yingsheng's case on May 31 after he appealed. On Aug 5, the high court held a private hearing of the case in Fuyang and overturned the murder conviction.

The high court told Yu he is entitled to ask for compensation from the central government and promised to coordinate efforts to help him settle down in Bengbu.

High court judges said they will also contact the relatives of deceased woman.

Yu could not be reached on Wednesday for comment.

His older brother, Yu Ningsheng, told news portal people.com.cn that Yu Yingsheng was undergoing a medical examination outside Anhui.

"He doesn't have a mobile phone. He has just been released and is in a daze. He needs some time to recover."

An unnamed source said Yu had been the assistant to the governor of Bengbu's Longzihu district. The ruling, the source said, devastated Yu's family.

The reversals in recent months prompted the Commission for Political and Legal Affairs of the Communist Party of China Central Committee to issue a guideline on Tuesday to prevent unjust or wrongful judgments.

Under the guideline, law enforcement and the judiciary system must bear a lifelong responsibility for their roles in wrongful judgments.

But the guideline's strongest wording came in its call to change the current judicial appraisal system, which evaluates the performance of law enforcement on the number of criminal cases that are solved and the number of suspects detained or prosecuted.

The guideline also addressed confessions obtained through torture. It reiterated the Criminal Procedure Law, saying all interrogations should be conducted in detention houses and recorded using audio or video equipment.

The guideline said the judiciary system must be independent of human interference in its decision-making.

Xinhua contributed to this story.