Gao Zhen, 70, and his brother Gao Qiang gained fame in the early 2000s for art touching on sensitive political topics like the Cultural Revolution, the Tiananmen Square protests and the legacy of Mao, who led China from 1949 until his death in 1976.

Their works include a sculpture of the Communist leader kneeling, titled "Mao's Guilt", and another called "Execution of Christ", in which several bronze statues of Mao aim rifles at one of Jesus.

Gao Zhen, who moved to the United States in 2022, was detained at his studio on the outskirts of Beijing during a visit to China in August 2024.

The artist -- whose name can also be written as Gao Shen -- was indicted in June last year on charges of "insulting... heroes and martyrs", according to Chinese Human Rights Defenders (CHRD).

On Tuesday, CHRD told AFP Gao was sentenced to three years in prison -- the maximum sentence for that crime -- at Sanhe City Court in northern Hebei province.

Chinese authorities appeared to be retroactively applying a 2021 law to works that Gao created between 2005 and 2009.

"(The) decision to convict Gao Zhen and sentence him to the maximum three-year prison term under this offence illustrate the authorities' determination to deter others from engaging in independent artistic expression," said Sarah Brooks, China director for rights group Amnesty International.

"No artist should face criminal punishment for creating work that challenges official narratives or encourages critical reflection on history," Brooks added in a statement.

According to Amnesty, Gao is due to complete his sentence next August, but has decided to appeal both the prison term and his conviction.

AFP's multiple calls to the court on Tuesday went unanswered.