Former Beijing party boss Chen Xitong has been released on medical parole after serving eight years of his 16-year jail sentence for corruption in one of the most high-profile cases to affect the top echelons of the Communist Party leadership.
Separately, former China Everbright Holdings chairman Zhu Xiaohua has also been released on medical parole after serving four years of a 15-year sentence for corruption.
Sources close to Mr Chen said the 76-year-old was recently released into a top Beijing military hospital for treatment of unspecified illnesses.
However, Mr Chen was not expected to regain complete freedom and was most likely to have his movements restricted due to parole conditions and political reasons, the sources said.
Authorities are now trying to determine the pay entitlements for Mr Chen, who was a Politburo member and the mainland's eighth-ranked leader before his fall from power in 1995 and imprisonment in 1998.
Mr Zhu, 57, was recently released and is now recuperating in Shanghai, where he first made his mark as a respected banker. He became one of the mainland's most visible financial officials before his imprisonment in 2002.
Friends of Mr Zhu said he had deliberately kept a low profile and his release was known to only a small group of friends and family.
Senior mainland officials who are sentenced to long prison sentences on corruption charges can usually gain freedom on medical parole after serving three or four years. But the release of Mr Chen came as a surprise to many observers in Beijing as previous reports indicated he had refused an offer of medical parole, insisting he be released unconditionally as he was innocent and not ill.
In 1995, the mainland leadership sacked Mr Chen as party secretary of Beijing, saying he was involved in a spate of corruption scandals also involving family members and associates, including former Beijing executive deputy mayor Wang Baosen , who later killed himself.
In 1998, Mr Chen was sentenced to 16 years' jail on charges of corruption and dereliction of duty.
But many of his supporters believed the sentence was politically motivated because Mr Chen was known as the leader of a party faction involved in a long and bitter rivalry with then president Jiang Zemin .
Many observers said Mr Zhu suffered a similar fate when he was sentenced to 15 years in prison in 2002, three years after he was first detained. He was convicted of accepting bribes worth 4.05 million yuan in stock and cash between 1997 and 1999, when he was chairman of China Everbright, one of the mainland's leading investment conglomerates.
Many believe he was a victim of the political manoeuvring among senior leaders in the run-up to the 16th party congress in which a major leadership reshuffle took place. He was known as a protege of former premier Zhu Rongji .