The head of Hong Kong's journalist union was charged with obstructing police on Monday, 10 days before he was set to leave the city and begin an overseas fellowship.
Ronson Chan, chairman of the Hong Kong Journalists Association (HKJA), was arrested earlier this month over a dispute with two officers who asked to see his identification while he was covering a residents' meeting at a public housing estate.
The police say Chan refused to provide his ID card and behaved in an "uncooperative" way despite multiple warnings.
He was charged Monday for obstructing a police officer, an offence that carries up to two years in jail, and will appear in court on Thursday.
Authorities have used a national security law and colonial-era sedition charges to crack down on dissent in Hong Kong after pro-democracy protests three years ago.
"I told them I do not understand the charge... I did not obstruct any police officers," Chan said outside the police station.
The journalist has disputed the police's account, saying he was asking the officers to explain why they had subjected him to a search and was cuffed before he could get his card out.
He also accused the officers of threatening him on the way to the police station, saying they made comments such as "let's see when you will die".
Hong Kong police have broad stop-and-search powers and residents have limited legal recourse to object to an ID check.
Chan had been planning to leave Hong Kong at the end of September for the six-month Reuters Institute fellowship programme at Oxford University.
Local media deemed critical of the government have faced a surge of police investigations and the city has plummeted down global press freedom rankings.
Hong Kong dropped 68 places to 148th in the annual press freedom index released by Reporters Without Borders (RSF) this year.
Local tabloid Apple Daily and online news platform StandNews -- which Chan used to work for -- were forced to close last year after executives were charged with national security violations, leaving hundreds of journalists out of work.
Like many now-shuttered civil society groups and pro-democracy unions, both Chan and the HKJA have faced repeated criticism from pro-Beijing media outlets.