Until a few weeks ago, Long Zhenyang held one of the top media jobs in south China.
He was the assistant chief editor of the Hong Kong Commercial Daily, one of three pro-Beijing newspapers in the Chinese territory.
His sudden resignation in February and stated intention to seek political asylum in the United States has jolted the local media community.
Mr Long, 47, has told BBC News that he left mainland China because he had been "persecuted" at the newspaper since late 2014, after he shared posts on his private social media account that were supportive of the pro-democracy protests in Hong Kong.
A devout Christian, the former journalist said he was also upset by a long-running campaign to remove crosses from churches in the eastern Chinese province of Zhejiang.
"I was very sad and devastated," he said from the San Francisco Bay Area, where he has been living with his family since last year. "I felt the Cultural Revolution was coming back."
'Hopes for reform shattered'
Once an ardent admirer of President Xi Jinping, Mr Long said he had lost hope in the Chinese leader.Image caption Mr Long's resignation letter said his "religion, beliefs and political views" meant he could no longer stay in his job
In an official resignation letter to Hong Kong Commercial Daily dated 5 February, he wrote: "In the past few years, the spirit of the Cultural Revolution seems to be quickly re-entering Chinese politics and society. Hopes for political or reform have all been completely shattered."
"Because of my religion, beliefs and political views, I can no longer continue to serve at the Chinese Communist regime-controlled Hong Kong Commercial Daily, so I have decided to resign my post."
Mr Long said he joined the newspaper in 1999.
According to its official website, Hong Kong Commercial Daily is one of several titles under the Shenzhen Press Group, which is directly controlled by the Communist Party.
Because of the newspaper's government affiliation, Mr Long held the rank of a junior government official, as well as the deputy editorship.
A Hong Kong-based spokeswoman for the Commercial Daily confirmed Mr Long's resignation, but offered no details.
A woman who answered the phone at the newspaper's Shenzhen office, where the former editor was based, also declined to give any information about the circumstances of his resignation.
'Most will simple obey'
Willy Lam, a reporter turned academic at the Chinese University of Hong Kong, said it was extremely rare to see a Chinese journalist go public with their criticism of the system, though he believes many of them are disillusioned and disgruntled.Image copyright Getty Images Image caption Journalists in China are seldom openly critical of the political system
"Given the draconian instructions given by the propaganda department and the increasingly rigid restrictions on what editorial line they can take, I imagine many journalists are not happy with their jobs. But most will simply obey the party line," he said.
Mr Long has claimed he was anti-Party for many years, even as he rose through the ranks at Shenzhen newspapers from junior reporter to senior editor.
"Over the past 20 years, I've written a lot of things I don't believe in," he said.
But he believes it was essays supporting the 2014 pro-democracy protests in Hong Kong that he shared privately, to his Wechat group, that got him into trouble.
He recalls being called into his boss's office at the end of that year to be reprimanded.
Later, he was informed of an official investigation into his conduct, which ended in 2015 with accusations against him of corruption and a violation of the one-child policy.
Though he was no longer a trusted hand, Mr Long said, he was not fired. He said he was relieved of his editing and managerial duties, but was allowed to continue writing for the newspaper.
After five Hong Kong booksellers disappeared at the end of 2015, possibly in connection with a book about the Chinese president, the newspaper editor said he decided to leave.
"The whole atmosphere deteriorated so much, I felt I had to leave the country," he said. "I know what they are capable of. They will just put you on national TV to confess. They can make you disappear."
Commercial Daily has not responded to requests for information.
But a journalist in Shenzhen familiar with Mr Long has confirmed that he was well known in media circles for his religion, and for sharing his political views liberally via social media.
Many, according to the journalist, believed the editor would eventually be punished, but others secretly admired his outspokenness.
As for Mr Long, he says he is studying at a Christian seminary in the Bay Area, and attending a local church. He has no plans to return to China, if the current regime remains in power.
Additional reporting by Grace Tsoi and Vincent Ni