The nephew of lawyer-activist Chen Guangcheng has been released from prison after serving a three-year, three-month sentence widely seen as retribution for his uncle's daring escape from house arrest.

Chen said in an email from the United States that Chen Kegui had returned to his home in eastern China on Wednesday and was seeking treatment for appendicitis and stomach ailments that had gone untreated in prison.

Chen Kegui, 35, was sentenced in 2012 after he fought with local officials storming his house in the wake of his uncle's escape and eventual flight to the United States after tense, high-level talks that nearly sparked a diplomatic crisis.

Chen, a blind, self-taught lawyer, is known for his activism against forced abortions and in the U.S. has redoubled his condemnation of China's leadership.