Chen Guangcheng is a Chinese human rights activist known for his work fighting against state-sponsored forced abortions.
Harassed for years by authorities, he fled to the US Embassy in Beijing in April 2012, ahead of a visit by then-Secretary of State Hillary Clinton.
After a tense month of negotiations, he was brought to the US by the Obama administration. At the time, he expressed his gratitude.
However, CNN reports he appeared at the Republican National Convention Wednesday and sang a very different tune.
There, Guangcheng praised President Donald Trump and accused President Barack Obama of having a "policy of appeasement" towards Beijing.
Relations with Beijing have plummeted since Trump took office, who has made being tough on China a key plank of his reelection campaign.