Campaigners were expecting the immediate release of Li Heping (pictured above, right) last month after he was given a three year prison sentence suspended for four years.
He had been held incommunicado for nearly two years.
It emerged on 28th April Heping had been convicted of "subverting state power" but he was not freed straight away despite receiving a suspended sentence.
Mervyn Thomas, Chief Executive of Christian Solidarity Worldwide, who has campaigned for Heping's release, said: "CSW welcomes the release of lawyer Li Heping."
Heping was among more than 300 people arrested during a crackdown which began in July 2015 by Chinese authorities on human rights lawyers and activists. He had been defending the rights of religious minorities and other victims of human rights violations.
According to his wife, Wang Qiaoling, Heping is being monitored closely. Restrictions on what he can do and say are expected to last throughout his suspended sentence.
Mervyn Thomas added: "While we are delighted to know that he has been reunited with his family, we remain concerned about the conditions on his release.
"Li Heping is innocent: like the other lawyers detained in this crackdown, he has been targeted because he defended the rights of Chinese citizens, including the right to freedom of religion or belief, even risking his own personal safety to do so.
"Therefore, a suspended sentence should not be seen as a 'lenient' measure. We call on the Chinese government to overturn this sentence and to investigate, in accordance with domestic and international law, reports that Li Heping and other detained human rights lawyers have been tortured in detention."