HONG KONG – Police in Hong Kong arrested a prizewinning journalist Tuesday whose work had exposed the authorities’ delayed response to a mob attack on anti-government protesters last year, intensifying concerns about a crackdown on press freedom in the semi-autonomous Chinese city.

The journalist, Choy Yuk-ling, who also goes by the name Bao Choy, is a producer for Radio Television Hong Kong, or RTHK, a public broadcaster. The network’s news programs have attracted official criticism for investigations into the Hong Kong police, who have been accused of using excessive force against the protesters and turning a blind eye to assaults on them.

Choy worked on some of the most notable inquiries into police conduct, including a prizewinning episode of the program “Hong Kong Connection” that examined the slow response by officers to a mob attack on a group of protesters and commuters in a train station on July 21, 2019.

Police said they arrested Choy on Tuesday afternoon for making a false statement about why she was obtaining license information from a publicly accessible database. Such offenses could be punishable with fines of $645 and six months’ imprisonment.

In an investigative documentary that aired in July, one year after the mob attack, RTHK journalists looked up the license plates of vehicles caught on video transporting the suspected assailants and traced them to community leaders in the territory’s outlying villages.

Hong Kong’s traditionally freewheeling news outlets have met with increased difficulties in recent years, including a loss of advertising from companies afraid to anger China and reporters arrested and attacked with pepper spray while covering last year’s protests. A new national security law imposed by Beijing at the end of June has compounded the risks for journalists, stifling reporting on potentially sensitive subjects.

Foreign news outlets in the city have also faced obstacles, including difficulty renewing visas for journalists. The New York Times said in July that it would move some of its operations from Hong Kong to Seoul, South Korea, citing visa delays and uncertainties created by the security law.

RTHK, which is a government department staffed in part by civil servants, has been under growing pressure from establishment lawmakers and pro-Beijing groups to curb its aggressive reporting, particularly about other government agencies.

The Hong Kong Police Force faced widespread criticism after protesters accused them of ignoring calls for help during the train station attack in the Yuen Long district. At least 45 people were injured when men carrying sticks and metal bars set upon commuters and protesters inside the station and aboard a subway train.

More than a year later, police have moved to decisively change the narrative about the assault. In August, police arrested a lawmaker who filmed the attack and was wounded during it. Police also said in August that it had taken them 18 minutes to arrive on the scene after receiving emergency calls and not 39 minutes, as they had previously said.