China has often accused "foreign forces" of trying to destabilize free-wheeling Hong Kong during the current pro-democracy protests, with a garrulous expat American emerging as a key target of attack.
Mark Simon, the right-hand man of pro-democracy newspaper magnate Jimmy Lai, has moved his family out of Hong Kong for safety and has been pressed to deny that he is a U.S. spy.
But, in interviews with Reuters, Simon insists he will not let a "relentless smear campaign" force him out of his home in the Asian financial hub and he still has plenty of stomach for the fight.
Large, loud and avowedly Republican, the 50-year-old has been portrayed across pro-Beijing media as a CIA agent - a charge also thrown at student protest leader Joshua Wong and an independent academic pollster, Robert Chung.
He's also a proud Catholic - something that links him to Lai and many other prominent figures in the Hong Kong democracy struggle.
Simon described Lai as an instinctive backer of underdogs rather than an "egotist" who believes that he will single-handedly change China.
"Jimmy's instinct is to size up the weak, and to size up the strong, and then instinctively protect the weak," he said.
"We are Hong Kong guys and we are Catholics."
The former British colony of Hong Kong, which returned to Chinese rule in 1997, has witnessed a month of protests calling on the Beijing-backed government to keep its promise of introducing universal suffrage.
The protests have for the most part been peaceful, with occasional clashes between the student-led protesters and Beijing supporters seeking to move them from the streets. China has expressed dissatisfaction about what it sees as foreign interference in an internal issue.
Hong Kong leader Leung Chun-ying recently echoed Beijing's concerns that foreign forces were behind the protests, but said the time was not right to reveal the government's evidence.
"I DON'T LIKE BULLIES"
Simon, who stands a broad and heavy-set 1.9 meters, said he was unafraid about staying in Hong Kong. But he said that after his address was published on-line he felt it wise to send his wife and two children back to the United States, unsure of what "nut-jobs" would be willing to do to impress Communist Party leaders in Beijing.
"I have a good job, I have a great boss, I have huge responsibilities and I am not going to let a bunch of jackass commies impose things on me," Simon said.
"I just don't like bullies acting like this... If I was 25 years younger I would be walking in these guys' bars looking for them."
Earlier this year, hundreds of emails and documents were stolen in a hacking attack on Lai's Next Media operation, some of them detailing the magnate's extensive, and well known, funding of Hong Kong's democratic activists.
They were then leaked en masse to Hong Kong media, including pro-Beijing mouthpiece papers that have focused on Simon's alleged role.
Hong Kong's anti-corruption force, the Independent Commission Against Corruption, is also investigating after public complaints over specific funding to lawmakers. Both Simon's and Lai's homes have been searched.
Simon has been in Hong Kong since the early 1990s and has worked with Lai since 2000, working earlier on media and on-line projects and more recently helping manage his extensive non-media investments.
Of his portrayal in pro-Beijing media as an "international man of mystery", Simon links the allegations against him back to his four years as a young civilian in the U.S. Navy as an intelligence analyst scrutinizing submarine developments.
He has also made no secret of his Republican activism, or his extensive contacts in the U.S. Congress, some of whom he meets during visits to Hong Kong.
"You've got 20 percent of America that thinks Barack Obama is not a U.S. citizen, OK, and in a place like Hong Kong you've got 30 percent of people who believe all this CIA stuff," he said.
He believes the U.S. government has no interest in meddling in Hong Kong but merely wants it to remain stable. And he doesn't believe China really thinks of him as a menace.
"If they really thought I was causing trouble, I wouldn't be here," he said. "They would have nailed me to the wall."