Taxi drivers defied Chief Executive John Lee Ka-chiu's calls to stop going undercover to report illegal ride-hailing services.
According to a video clip uploaded on Facebook, a driver is seen recording a passenger in his car with his cellphone and suspects he is pretending to be an undercover police officer.
The video also shows that the drop-off zone is outside M+ Museum in the West Kowloon Cultural District.
"You are not a policeman, right?" the driver asks. "You really like to go undercover, don't you?"
The passenger responds: "Why can't I investigate by myself? Are you intimidating me? I am now very afraid."
The driver replies: "I am also frightened by you. Now what?"
A man, suspected to be an accomplice of the undercover passenger, stands in the middle of the road to block the car and instructs the driver to stop behind a police vehicle that is already at the scene.
The passenger complains to a police officer, claiming that he is being "criminally intimidated" by the driver.
While the police officer is recording the driver's details, two men who are also "involved in the undercover operation" start an argument with the driver.
The accomplice then starts to provoke the driver with foul language: "Do you know you do not have a license [to carry passengers]?"
"I know, and I like it, what can you do to me?" the driver says.
The accomplice continues: "He is breaking the law, how come the police officer is returning his license?"
"Yes, I am not afraid of you, come hit me, come on, hit me," the driver replies.
The two working as "undercover operators" try to take a picture of the driver's face with their phones.
Another video of the incident posted on Facebook shows the same driver getting out of his vehicle and having a heated argument with the two men and possibly a third man.
A quarrel ensues and police officers separate them.
The driver is then released, but the "undercover operatives" are still being questioned by the officers.
"Time to start your shift," the driver says. "Continue going undercover, remember to hail my vehicle again."
Police confirmed that they received eight complaints from outside the West Kowloon M+ Museum on Saturday afternoon, but they have not yet made any arrests.
This came after Lee urged people last week not to take the law into their own hands and unknowingly risk breaching it.
Chow Kwok-keung, chairman of the Hong Kong Taxi and Public Light Bus Association, has said law enforcement should be done by relevant government departments and that he opposes drivers going undercover.
michael.shum@singtaonewscorp.com
A woman flags down a taxi. Cabbies have been urged not to take the law into their hands. SING TAO